I I 71-23,163 BLOOMFIELD, Gary James, 1940A DESCRIPTIVE STUDY OF SENIOR DRIVER ACCIDENT RECORDS IN THE STATE OF MICHIGAN BY AGE GROUP, SEX, URBAN AND RURAL RESIDENCY. Michigan State University, Ph.D., 1971 Education, curriculum development U niversity M icrofilms, A XEROX Com pany , A nn A rbor, M ichigan 0Copyright by GARY JAMES BLOOMFIELD 1971 A DESCRIPTIVE STUDY OF SENIOR DRIVER ACCIDENT RECORDS IN THE STATE OF MICHIGAN BY AGE GROUP, SEX, URBAN AND RURAL RESIDENCY By Gary James Bloomfield A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY College of Education 1971 PLEASE MOTE: Some pages have small and indistinct type. Filmed as received* University Microfilms ABSTRACT A DESCRIPTIVE STUDY OF SENIOR DRIVER ACCIDENT RECORDS IN THE STATE OF MICHIGAN BY AGE GROUP, SEX, URBAN AND RURAL RESIDENCY By Gary James Bloomfield Statement of the Problem In the past, the proportion of senior drivers to the total driving population has been relatively small and very little concern was expressed in regard to the driving problems of this age group. changed substantially. However, this situation has Today the senior driver is an important part of our driving population. The senior driver is a significant factor in the total traffic acci­ dent picture, for his numbers have been expanding each year and it is predicted that this growth among senior drivers can be expected to continue. Driving is often the only means by which the senior citizen can obtain meaningful and interesting activities. Due to lack of convenient transportation, the senior citizen population needs to drive not only for diversified interests but for basic necessities in living. The senior Gary James Bloomfield citizen population needs to drive if they are to reach shopping centers, attend church, receive medical attention, and participate in community activities. Thus, there was a need to acknowledge this age group as an important part of our driving population and to become acquainted with the driving accident problems brought about by advancing years. Because of the importance of understanding more about this segment of the driving population, it was the purpose of this study to determine whether senior drivers’ accident records differed when categorized by age group, sex, urban and rural residency. Description of the Methods, "Technique, and Data Used The population from which the sample for this study was selected consisted of those senior drivers whose names and driving records were recorded in the Michigan Depart­ ment of State, Driver and Vehicle Services. All driving records were in alphabetical order on 100 computer reels accounting for 5,000,000 drivers. One reel, from which to secure a sample of senior drivers, was randomly selected. There was no reason to believe that the driving performances or the proportion of senior drivers was any different as each reel was a cluster of heterogeneous drivers in the state of Michigan. A computer readout sheet was obtained containing 3,340 driving records on each senior driver's residency, Gary James Bloomfield sex, age and accident record. Only those senior driver records indicating an accident involvement were used in final analysis. Each senior driver's age at the time of the accident was determined and those who had an accident at age 65 years or above were recorded in the age group the accident occurred. Urban and rural residency was determined according to zip code of the senior driver's address and the United States Bureau of Census. The study programmed questions in order to derive data pertaining to the following: senior drivers involved in accidents, cited and non-cited accidents among senior drivers, violation factors among senior drivers, under the influence of alcohol in senior driver accidents, number of vehicles in senior driver accidents, fatalities in senior driver accidents and season in which senior driver acci­ dents occurred. The Major Findings 1. Michigan senior drivers had a higher accident rate than the national senior driver rate. 2. Senior drivers between the ages of 65-69, who were males and living in an urban area were more likely to be involved in an accident. 3. Senior drivers were more likely to have only one accident during a five year age period. 4. The majority of senior drivers when involved in an accident were cited as being at fault. Gary James Bloomfield 5. a fatality. The majority of senior driver accidents involved This fatality involvement increased when senior drivers were cited as being at fault. 6. The majority of senior drivers were cited as being at fault for "failed to yield the right of way" and "failed to stop in the assured clear distance ahead." 7. Cited for being under the influence of alcohol was not a major contributing factor in accidents among senior drivers. 8. Senior drivers used their automobiles through­ out the year, as accidents were apparent for all seasons. ACKNOWLEDGMENTS To Dr. Robert 0. Nolan, my sincere appreciation who as my major advisor and chairman of my guidance commit­ tee, provided counsel throughout my graduate program and all phases of this study. To the other members of my guidance committee, Dr. Dale V. Alam, Dr. Robert E. Gustafson and Dr. William A. Mann for their helpful suggestions and assistance. To the Michigan Department of State, Data Process­ ing Department and to Jean Pixley for assistance in obtain­ ing the data necessary for this study. To my wife, Sandee, for her love, patience, constant encouragement and support for which I will always be grateful. ii TABLE OF CONTENTS Page ACKNOWLEDGMENTS ....................................... ii LIST OF T A B L E S ...........................................Vi LIST OF F I G U R E S ........................................ viii LIST OF A P P E N D I C E S ....................................... ix Chapter I. THE P R O B L E M ................................ 1 United States Senior Citizen Population Growth .................................... 1 Michigan Senior Citizen Population Growth . 3 Senior Driver Population Growth . . . . 7 Factors Related to the Senior Driver Population .............................. 9 Driver Licensing Factors Related to Senior D r i v e r s .....................................11 Other Factors Related to Senior Drivers . 13 The P r o b l e m .....................................14 Statement of the P r o b l e m .................... 14 Purpose and Objectives of the Problem . 15 Importance of the P r o b l e m ................. 16 Definition of T e r m s ...........................18 Senior Citizen . . . . . . . . . 18 Senior Driver .......................... 18 Senior Citizen Population.................... 18 Senior Driver Age Group ................ 18 Urban R e s i d e n c y .............................. 18 Rural R e s i d e n c y .............................. 19 Violation Factors ....................... 19 Cited A c c i d e n t s .............................. 19 Non-cited Accidents .................... 19 Limitations of the S t u d y .................... 19 Organization of the Remaining Chapters . . 20 II. REVIEW OF THE LITERATURE ON THE SENIOR DRIVER Introduction ............................. Michigan Senior Citizen Residency . . . Age in Relation to Miles Driven . . . . Aging and D i s e a s e .............................. iii 21 21 21 22 25 Page Chapter Accident Involvement ...................... 27 S u m m a r y ...................................... 35 III. P R O C E D U R E ...................................... 37 Population and Sample ................... 37 Distribution of the S a m p l e ................... 38 Methods of Processing the Data . . . . 39 Determining the Sample for Analysis . . 41 Processing the D a t a ...................... 49 Methods for Descriptively Analyzing the D a t a ...................................... 50 S u m m a r y ...................................... 51 IV. THE F I N D I N G S ...................................52 Single and Multiple Accident Involvement Among Senior D r i v e r s ...................... 53 Cited and Non-cited Accidents Among Senior D r i v e r s ...................................55 Violation Factors in Cited Accidents Among Senior D r i v e r s ...................... 57 Cited for Under the Influence of Alcohol in Accidents Among Senior Drivers . . . 58 Cited and Non-cited Accidents Involving One and Two or More Vehicles Among Senior D r i v e r s ...................................61 Violation Factors in Cited Accidents Involving One and Two or More Vehicles Among Senior D r i v e r s ...................... 63 Fatalities in Cited and Non-cited Accidents Among Senior Drivers . . . . 66 Violation Factors in Cited Accidents Involving Fatalities Among Senior D r i v e r s ...................................68 Cited and Non-cited Accidents by Season Among Senior D r i v e r s ...................... 70 S u m m a r y ......................................74 V. SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS . 75 S u m m a r y ......................................75 Statement of the P r o b l e m ................... 75 The Methods of P r o c e d u r e ................... 76 The Major F i n d i n g s ......................... 78 Single and Multiple Accident Involvement. 78 Cited and Non-cited Accidents . . . . 79 Violation Factors in Cited Accidents . . 80 Cited for Under the Influence of Alcohol in A c c i d e n t s ............................ 80 iv Page Chapter Cited and Non-cited Accidents Involving One and Two or More ....................... 81 Vehicles Violation Factors in Cited Accidents Involving One and Two or More V e h i c l e s ................................. 81 Fatalities in Cited and Non-cited A c c i d e n t s ................................. 81 Violation Factors in Cited Accidents ................ 82 Involving Fatalities Cited and Non-cited Accidents by Season . 83 C o n c l u s i o n s .................................... 83 Recommendations . . . . . . . . . 84 D i s c u s s i o n .................................... 86 Accident Site in Relation to Residency . 86 Recommendations for Further Research . . 87 BIBLIOGRAPHY .......................................... 89 A P P E N D I C E S ..............................................93 v LIST OF TABLES Table 1. Page Distribution of Michigan's senior citizen population by age . . . . . . . . . 2. Distribution 3. Distribution of 611 senior drivers with an accident age 65 or o l d e r ........................42 4. Distribution of senior drivers with accident records by zip c o d e ........................... 46 5. Senior drivers involved in accidents by age group, sex, and r e s i d e n c y .................... 54 6. Accidents, cited and non-cited, by age group, sex, and r e s i d e n c y .............................. 56 7. Violation factors in cited accidents by age g r o u p ........................................... 59 8. Violation factors in cited accidents by sex and r e s i d e n c y ................................. 60 9. Vehicle involvement by age group, sex, and r e s i d e n c y ........................................ 62 10. of 3,340 senior driver records 22 Violation factors in cited accidents involving one vehicle by age group, sex, and residency . 40 64 11. Violation factors in cited accidents involving two or more vehicles by age group, sex, and r e s i d e n c y ................................. 65 12. Fatalities in cited and non-cited accidents by age g r o u p ..................................... 67 13. Fatalities in cited and non-cited accidents by sex and residency ................. 69 14. Fatalities per violation factor by age group, sex, and r e s i d e n c y .......................... 71 Table Page 15. Accidents per season by age group 16. Accidents per season by sex and residency . vii . . . . 72 . 73 LIST OF FIGURES Figure Page 1. United States population growth from 1940 2. Michigan 3. Per cent of drivers 65 years of age and older per all drivers in the United States . population growth from 1940 . . . 4 . . 6 8 4. Distribution of Michigan*s senior citizen p o p u l a t i o n ................................... 23 5. Zip code districts in the state of Michigan viii . 45 LIST OF APPENDICES Appendix A. Page Department of State Data Processing Division Burroughs Magnetic Tape Layout ............. 94 B. United States Census Maps, Urbanized Areas-** M i c h i g a n ........................................ 96 C. Zip Code Areas Considered Urban in the State of Michigan .................... . . . . 1 0 1 D. Computer Code List Michigan Department of State Police P o s t s ............................. 10 3 ix CHAPTER I THE PROBLEM In the past, the proportion of senior drivers to the total driving population has been relatively small and very little concern was expressed in regard to the driving problems of this age group. changed substantially. However, this situation has Today the senior driver is an important part of our driving population. The senior driver is a significant factor in the total traffic acci­ dent picture and in the future he will increasingly become a more important factor. His numbers have been expanding each year and it is predicted that this growth among senior drivers can be expected to continue. United States Senior Citizen Population Growth The number of persons 65 years of age and older has increased rapidly in the past several decades. The United States census figures show that in 1940 there were 9,000,000 (million) persons 65 years of age and older.^ In 1960 this age group had increased to 16,207,000 (million) 1United States Department of Commerce, Population Estimates (Washington, December, 1967), p. 6. 1 persons or 9.1 per cent of the American population. 2 The census figures based on 1966 Population Estimates, indi­ cated that the age group, 6 5 years of age and older, represented 9.4 per cent of the American population or 3 approximately 18,500,000 (million) persons. These figures reflect an average annual increase of 365,384 persons 6 5 years of age and older. has doubled in 26 years (thousand) Thus this age group (1940-1966). Continued substantial increases in the population 6 5 years of age and older have been indicated by the United States Population Estimates. For 1970, it is estimated that those who are 65 years of age and older will number approximately 19,600,000 (million) persons or 9.6 per cent of the American population. Projections further estimate that in 1980 those who are 65 years of age and older will mount to 23,000,000 (million) persons or 10.2 per cent of the American population. Not until 1990 when the senior citizen population has reached 27,000,000 (million) persons or 10.6 per cent of the American population will the decline in births that occurred during the 1920's and 1930's begin to affect 2 United States Department of Commerce, 1960 Census of Population (Washington, 1960), pp. 1-153. 3 United States Department of Commerce (December, 1967) , p. 6. 3 -the size of this age group. 4 Estimated figures reflect an average annual increase of 340,000 (thousand) persons 65 years of age and older for the next ten years 1980). (1970- Further projection of these figures indicates that an average annual increase of 400,000 (thousand) persons 65 years of age and older will occur during the years 1980-1990. Figure 1 shows graphically the population growth rate of the United States as well as the growth rate of the senior citizen population since the year 1940. From 1940 to 1960 the rate of growth was based upon United States Census figures. Increases in growth rates from 1970 to 1990 were based on projected estimates of popula­ tion census. Between 1940 and 1970 the total United States population had increased 119 per cent while the United States senior citizen population had increased 58 per cent. Michigan Senior Citizen Population Growth The state of Michigan has experienced a substantial growth in senior citizen population. In 1950, the senior citizen population represented 7.2 per cent of the state's population or approximately 4 56,115 (thousand) persons. The senior citizen population grew to 638,184 ^Ibid. (thousand) 4 200% .. 180% .. 140% .. Growth Rate form 1940 160% .. 1 0 0 %.. 80% .. 60%.. 40% .. 20 %.. 1940 1950 1960 1970 Years 1980 1990 Figure 1.— United States population growth from 1940. Key: Total U. S. population « _____ 65 years and older population * ---- 5 persons in I960, which represented 8.2 per cent of the Michigan population. 169,733 This represents an increase of (thousand) persons 65 years of age and older from 1950 to 1960. Continued increases in the Michigan population 65 years of age and older were indicated by the Population Estimates.6 For 1970, the senior citizen population was projected to be approximately 759,000 (thousand) persons, or 8.9 per cent of the Michigan population. Projecting further, it is estimated that by 1980 those who are 65 years of age and older will include approximately 899,000 (thousand) persons or 9.5 per cent of the Michigan popula­ tion. For 1985, the state's senior citizen population will be approximately 989,000 (thousand) persons or 9.9 per cent of the Michigan population. These figures clearly denote the significant growth of Michigan's senior citizen population. Figure 2 shows graphically the population growth rate for the total Michigan population as well as the Michigan senior citizen population growth since the year 1940. From 1940 to 1960, the rate at which Michigan's population increased, was based upon United States Census figures. Increases in population growth rates from 1970 5 United States Department of Commerce, 1960 Census of Population Michigan (Washington, 1960) , p. 2TI ^United States Department of Commerce, Population Estimates (Washington, October, 1967), p. 6. 6 2 0 0 % .. 180% - 1940 from 120 % 100 % .. Growth 140% . Rate 160% - - 80% 60% .. 40% .. 20% 1940 1950 1960 1970 Years 1980 '85 1990 Figure 2.— Michigan population growth form 194 0. Keys Total Michigan population = 65 years and older population = ---- 7 to 1990 were based upon projected estimates of population growth. Between 1940 and 1970 the total state of Michigan population had increased 129 per cent while the Michigan senior citizen population had increased 60 per cent. A major factor in the increase of the senior citizen population can be attributed to the outstanding reductions in death from infectious diseases. result, life expectancy has increased. As a The average life expectancy at birth has increased from 4 7.3 years in 1900 to 70.2 years in 1965.7 Senior Driver Population Growth As the senior citizen population increased so did the senior driving population. Figure 3 shows graphically the increase in percentage rate of senior drivers to all drivers in the United States beginning in the year 1940. Between 1940 and 1959 the percentage of drivers in the United States age 65 years and older was estimated to have increased from 3 per cent to about 6.8 per cent of the g driving population. From 1959 to 1968 the percentage of drivers in the United States age 65 years and older was estimated to have increased from 6.8 per cent to 8.5 per 7 Luman H. Long, e d . , World Almanac and Book of Facts 1969 (Cleveland, 1969), p. 763. Q Burton W. Marsh, "Aging and Driving," Traffic Engineering, XXXI (November, 1960), 12. 8 10% „ 6% - 4.8 4% .. Growth Rate from 1940 8%.. 2%.. 1940 1950 1960 1970 Years Figure 3.— Per cent of drivers 65 years of age and older per all drivers in the United states. cent of the driving population. q The number of senior drivers was estimated at 1.36 million in 1940. In 1959 the number of senior drivers had increased to an estimated 5.71 million.10 The number of senior drivers has increased steadily and by 1968, the senior driving population included an estimated 8.9 million persons.11 The percentage of senior drivers in proportion to the total driving population in the state of Michigan was not recorded until 1966. In that year the percentage of drivers in the state 65 years of age and older was esti­ mated to be 7.0 per cent of the Michigan driving popula12 tion. Data indicates that the senior driving population has increased each year with the latest estimate being 1968 which revealed 522,500 (thousand) senior drivers who comprised 9.5 per cent of the total Michigan driving popu. .. 13 lation. Factors Related to the Senior Driver ~ Population A factor relating to the anticipated growth in numbers of senior drivers has been the relationship of the 9 National Safety Council, Accident Facts 1969 (Chicago, 1969), p. 54. 10Marsh, p. 12. 11National Safety Council, p. 54. 12 Department of State Police, Michigan Traffic Accident Facts 1966 (Lansing, 1966), p^ &. 1^Department of State Police, Michigan Traffic Accident Facts 1968 (Lansing, 1968), p. 16. 10 automobile age to the population. During the 1920's the number of motor vehicles and drivers began to increase greatly. Many of the drivers who were then in their late teens and early twenties are now 65 years of age and older. Increased desire on behalf of the senior driving population to continue to drive past age 65 accounts for increased numbers of registrations among this age group. To many senior citizens, driving has been the link to interesting and purposeful activities of life. With the great and growing dispersion to places of residence in suburban areas, the senior driver has needed to drive. Additional factors include a greater number of persons who enjoy improved health during their senior years, and an increasing number of women drivers who have reached 6 5 years of age. With the advent of a shorter work week and the adoption of better retirement plans and attendant bene­ fits, more retirements at age 65 have resulted. has become a popular use of leisure time. Driving In the past it was economically impossible for many senior citizens to continue to drive. Improved economic status among many who reach 65 years of age now permits vehicle ownership whereas once it was a luxury. Our American automobiles are now more dependable and with the advent of power steering and power b r a k e s , are mechanically easier to operate. In addition, the 11 convenience and availability of better roads and service facilities have made driving more attractive to the senior driver. In the years to come there will continue to be a large number of senior citizens who will continue to drive through their later years. No longer is the senior driver an insignificant part of our total driving population. Driver Licensing Factors Related to Senior Drivers The anticipated increase of senior drivers in the United States population has presented a problem to licensing authorities and other persons in the field. These people are faced with the responsibility of recom­ mending an age at which a person should or should not be permitted to retain his driving license. In some states it is mandatory that drivers who reach a certain age level be retested in order to renew their operator's license even though they may never have 14 been identified as problem drivers. Maryland is cur­ rently a state which may deny an applicant a license solely upon the basis of age. In that state, any driver who has reached 70 years of age and wishes to have his license renewed must provide proof of prior satisfactory operation of a vehicle or present a certificate from a 14 John A. Dimling, Driver Licensing and Performance Vol. II/ Survey of State Practices (Washington, 1968), pp. 3-4. 12 physician indicating that the applicant is in satisfactory physical and mental condition in addition to his being retested. Ten other states presently have formal provisions for retesting drivers selected on the basis of age. Indiana, Maine, and New Hampshire require drivers attain­ ing age 75 to submit to retesting. Nevada, Delaware, Arizona, and the District of Columbia retest drivers attaining age 65. 15 Illinois retests those drivers over 69 years of age. Alaska and Rhode Island require drivers 16 reaching 70 years of age to undergo retesting. Most states have instructed their driver license examiners to request drivers, who appear to be losing skill because of age to take specific tests before their license can be renewed. In these states the selection for such retesting is at the discretion of the examining staff. Michigan currently operates under such a plan. There have been bills presented to the Michigan legisla­ ture requiring proof of a physical examination by a physician at a specific age passed. (65-70) but none have been Currently, the Secretary of State's office, 15"The Senior Driver" (editorial), Traffic Digest and Review, XIII (March, 1965), 3. 16Dimling, pp. 3-4. 13 Driver License Department, has received federal money to establish a Medical Advisory Board consisting of five doctors from five different disciplines (medical doctor, opthamologist, optometrist, psychologist, gerontologist). An applicant applying for a renewal driver's license may be referred by the examiner to his family physician.* The Board will decide whether an applicant is unfit to drive an automobile based upon the prognosis from the family physician. However, the Medical Advisory Board is still at the planning stage and has yet to be approved by the Michigan Legislature. A test for visual acuity and peripheral vision is currently given to all renewal applicants regardless of age. The increased number of senior drivers and special problems relating thereto, as well as inconsistencies in the driver licensing process have caused confusion and concern among driver licensing authorities. Other Factors Related to Senior Drivers For numerous senior drivers the difficulty in obtaining adequate automobile insurance coverage at prices which they can afford is a problem. Automobile insurance rates among senior drivers can be a real financial burden. Insurance companies have been noted to raise the insurance rate because a driver has reached a certain age regardless of his driving record or have dropped a senior driver from the company for no reason other than age. Many insurance 14 companies have refused to accept new automobile insurance business from persons 65 years of age. Obtaining auto­ mobile insurance for the senior driver becomes even more complex due to the inconsistency of automobile insurance coverage and rates in each state. Satisfactory adjustment to growing old is for many, very difficult. A basic need for humans is to have a sense of personal worth and to feel needed. Yet, many senior citizens no longer have a regular job nor the responsibility for the caring of loved ones in the home. The report of The White House Conference on Aging brought out that, as with people of all ages, the senior citizen wants the right to be useful and to live with dignity through satisfying, worthwhile physical and mental activities, employment, voluntary service and creative activities which develop and keep mental resources. The senior citizen including the retiree group, want to remain a part of the community and not become isolated from con17 tacts with people of other ages. The Problem Statement of the Problem Driving is often the only means by which the senior citizen can obtain meaningful and interesting activities. ^ U n i t e d States Department of Health, Education, and Welfare, The Nation and Its Older People (Washington, 1961). 15 Furthermore, the senior citizen needs to drive not only for diversified interests but for basic necessities in living. Due to lack of convenient transportation, the senior citizen population needs to drive if they are to reach shopping centers, attend church, receive medical attention, and participate in community activities. Thus, there is a need to acknowledge this age group as an impor­ tant part of our driving population and to become acquainted with the driving accident problems brought about by advancing years. Purpose and Objectives of the Problem Because of the importance of understanding more about this segment of the driving population, it was the purpose of this study to determine whether senior drivers' accident records differed when categorized by age group, sex, urban and rural residency. It was proposed that meaningful data could be obtained by using the following specific questions as a guide to investigate this problem: 1. Does the per cent of senior drivers involved in one accident and two or more accidents differ when categorized by age group, sex, urban and rural residency? 2. Does the per cent of accidents, cited and non-cited, among senior drivers differ when categorized by age group, sex, urban and rural residency? 16 3. Do the violation factors in cited-accidents among senior drivers differ when categorized by age group, sex, urban and rural residency? 4. Does under the influence of alcohol become a factor in accidents among senior drivers when categorized by age group, sex, urban and rural residency? 5. Does the per cent of accidents, cited and non-cited, among senior drivers involving one vehicle and two or more vehicles differ when categorized by age group, sex, urban and rural residency? 6. Do the violation factors in senior driver accidents involving one vehicle and two or more vehicles differ when categorized by age group, sex, urban and rural residency? 7. Does the per cent of fatalities in accidents, cited and non-cited, among senior drivers differ when categorized by age group, sex, urban and rural residency? 8. Do the violation factors in senior driver accidents involving fatalities differ when categorized by age group, sex, urban and rural residency? 9. Does the per cent of senior driver accidents, cited and non-cited, by season differ when categorized by age group, sex, urban and rural residency? Importance of the Problem Attention needs to be given to the senior driver, for mobility and safe driving are important to this age group. To date no state-wide study has been done which concerns itself solely with the senior age group of drivers. Therefore, this investigation using accident records among senior drivers could make a significant contribution to the field of traffic safety in the follow­ ing m a n n e r : 17 1. 4.4.4 18 The Federal Highway Safety Program Standard calls for a program of adult driver training and retraining. This study could assist in the identification of those age groups within the Michigan senior driving population that are having accident problems. It will further assist in identifying those violation factors which are predominant among each group in urban and rural areas. Certainly this type of information could be beneficial in structuring a re-education curriculum. 2. Driver licensing officials will have a better understanding of the senior citizen driver with respect to the implications for driver licensing procedures. It could assist those persons with the responsibility for recommending an age requirement for re-examination. The study may further assist the driver improvement program in identifying those violation factors which are pre­ dominant among the senior driver age group in urban and rural areas. 3. The findings of this study could serve as a source of information to insurance companies in alleviat­ ing the confusion and inconsistency of senior driver insurance rates. 4. The senior driver, himself could better evaluate his driving performance by being informed of the 18 United States Department of Transportation, Highway Safety Program Standards (Washington, 1967). 18 difficulties present within his age group, sex, and urban and rural residency. Definition of Terms Senior Citizen A person whose age is 65 years or older and resides in the state of Michigan. Senior Driver A person whose age is 6 5 years or older and holds a valid Michigan driver's license as of 1969. Senior Citizen Population Those persons whose ages are 6 5 years or older and reside in the state of Michigan. Senior Driver Age Group Those senior drivers whose ages fall within one of the following groups: 65-69, 70-74, 75-79, 80-84, 85-89, 90-94, 95-99. Urban Residency An area which contains at least one city of 50,000 persons or more in 1970, as well as the surrounding closely settled incorporated places and unincorporated 19 areas. This area does not include an entire county in Michigan. 19 United States Department of Commerce, 1960 Census of Population, p. xxvi. 19 Rural Residency An area which has a city of less than 50,000 persons in 197 0. This area may include an entire county in Michigan. Violation Factors Those factors listed on the accident record indicating a charged driving offense as recorded by the investigating law enforcement officer. offense is not a court conviction. A charged driving This information was not available due to judicial delays. Cited Accident The accident record indicated the driver had been charged and ticketed for a violation in connection with an accident. Non-cited Accident The accident record indicated the driver was involved in the accident but not charged with a violation. Limitations of the Study The study was limited in the following manner: The driving records in the state of Michigan were kept on file for a period of only six years. Therefore, was not possible to obtain the entire accident record oack to age 6 5 years of those senior drivers in the older age groups. For this reason each group and the computed it 20 percentages were treated as separate entities in so far as age, sex and urban and rural residencies were concerned. Organization of the Remaining Chapters Chapter II contains a detailed review of the litera ture on the senior driver. Chapter III describes the sampling methods, procedures carried out and analysis techniques used. Chapter IV gives a descriptive analysis of the senior drivers' accident records by age group, sex, and urban and rural residency derived from a computer readout sheet of driving records. Chapter V presents the summary, conclusions and recommendations. CHAPTER II REVIEW OF THE LITERATURE ON THE SENIOR DRIVER Introduction It was indicated in Chapter I that the senior driver now represents a significant part of our driving population and will continue to do so for years to come. This chapter will present a review of the literature con­ cerned with the senior driver as related to this study. Michigan Senior Citizen Residency It was interesting to note the population density of senior citizens throughout the state of Michigan and projected figures for the future. The most significant increases occurred in the metropolitan counties. In 1965 almost one-half of the total population 65 years of age and older (344,406) was contained in only four of Michigan’s counties. They included Genessee, Macomb, 20 Oakland, and Wayne. For 1970, it was projected that over one-half of the senior citizen population (377,307) will live in these 20 University of Michigan and Wayne State Univer­ sity, Institute of Gerontology, Michigan Facts on A g i n g , Report No. 2 (Ann Arbor, 1967). 21 22 same counties. Thirteen of the smaller counties housed one-quarter of the total senior citizen population, while the remaining quarter were scattered throughout the other 66 counties (see Figure 4 and Table 1). 21 TABLE 1.— Distribution of Michigan's senior citizen popula­ tion by area. Item 1965 Per Cent of Sr. Pop. 1970 Per Cent of Sr, Pop. Upper Peninsula 34,556 5.00 34,478 4.63 Lower Peninsula Northern Part (30 counties) 48,436 7.01 48,798 6.56 Lower Peninsula Southern Part (34 counties) 272,702 39.51 283,285 38.08 Detroit Area (4 counties) 334,406 48.45 377,307 50.72 Total Population Senior Citizens 690,100 99.97 743,868 99.99 Age in Relation to Miles Driven The increased percentage of senior drivers among the driving population not only paralleled the growth of the senior citizen population but remained consistent with the fact that more people are reaching age 65 and have grown 21 University of Michigan and Wayne State University. 23 PENIN KHootciAir -H / lmahi NINSULA = Over one-half of the total population age 65 and over (4 counties) _J HMt fff' ffA - one-quarter of the '////j total population age 65 - 4i ** T , (n o r t h e f In H W A vQ O L j O S C C O IA , j U — I L_,_.T {-^ A K j G lA M n N j ■VHillA NICOSIA and over (13 counties) (jtAllOI = under one-quarter of the total population age 65 and over (66 counties) (OMA I CLINTON L. IA 1 Q N LOWER PENINSULA (SOUTHERN PART) Figure 4.— Distribution of Michigan's Senior Citizen population projected for 1970. m 24 up in a society in which the automobile has become an integral part. A study by Beadenkopf, et a l . brought out that the impact of the increase in the absolute number of drivers in older groups seemed dampened somewhat by the decline in exposure shown by these groups. Male drivers started to exhibit a decline in the number of miles driven at the age of 55. This decline, while sharp from the ages 55 to 65, was even more so from the ages 65 to 75. 2 2 The median mileage per year in the 50 to 59 age group was approximately 12,000 miles, in the 60 to 69 age group the median was 10,000 miles and in the 70 to 23 89 age group it was 3,500 miles. Other reports indi­ cated the same drop in mileage and change in exposure characterized by a decrease in per cent of travel on main rural roads and in nighttime travel. 24 National figures showed the ratio of male to female senior drivers increased substantially within the 6 5 and over age group. The difference became even more marked as age increased, indicating a more rapid tapering 22 W. G. Beadenkopf, et a l ., "An Epidemiological Approach to Traffic Accidents," Public Health Reports, Vol. 71, No. 1 (1956), 15-24. 23 American Automobile Association, Age, Exposure and Accidents (Washington, 1964). 24 United States Department of Commerce, Dri v e r1s Licenses 1965 (Washington, 1965). 25 off of driving behavior among females in spite of their 25 longer life expectancy. Males represented 70 per cent of the driving population 70 years of age and older. Aging and Disease Studies recognized that chronological age was not a sound criteria for appraising driving competence. Age in respect to driving is a multidimensional variable, and functional age is a far better evaluation. Unfortunately, no suitable criteria seems to exist for determining 26 functional age. Birren held that human chronological age represented different points on a young-old continuum where biological, psychological, and sociological view­ points must be considered somewhat independently. In each of these areas the individual "ages" at a different rate and according to a characteristic pattern. The Committee on Aging of the American Medical 27 Association concluded that no disease entity or physical or mental condition resulted from or was related to the passage of time. Arteriosclerotic heart disease, high blood pressure, arthritis and cancer are found in the 25 United States Department of Transportation, Drivers' Licenses 1966 (Washington, 1966). 26 J. E. Birren, "Research on the Psychological Aspects of Aging," Geriatrics, XVIII (1963), 393-403. 2^Fredrick C. Swartz, "Aging 1968," Michigan Medicine, Vol. 67, No. 9 (1968), 591-596. 26 youngster; measles, mumps, chicken pox and poliomyelitis are found in the oldster. More often it was indicated that the degenerative diseases of man resulted from the impact of environment. In laboratory studies, diseases were found to occur in animals exposed to hunger, extremes of temperature, lack of oxygen, infections, loss of blood or fear with little relationship to the age of the animal. In other laboratory studies the environment was regulated in the direction of protection for the individual from the effects of environ­ ment and the members lived for an unbelievably long time. Chronic illnesses and long term care cases resulted from the recurring and irritating effects of environment and not the passage of time. Continuing with this concept but not really coming under effects of environment were the pot belly and flabby muscles which resulted from the lack of exercise, the loss of habits of study and forget­ fulness that comes when the mind was not used, and the painful knees and flat feet that come from long-time 28 pounding by too much weight. While the age of 65 years was strictly an arbitrary point in terms of chronological age and the human organism's environment, it seemed an adequate choice. At the age of 65 years, retirement began, income usually ^8Swartz, p. 594. 27 decreased, social security benefits became available and affiliations began to change. These external factors caused, in turn, internal changes in the human organism. It is believed that some of the external changes forced upon an individual reaching 65 years are instrumental in producing characteristic differences attributed to those over 65 years of age. It is also believed that these external changes contribute to some of the accidental producing situations in which people over 65 years find 29 themselves. In much of the literature reviewed, chronological age was used as a matter of convenience for the research criteria; in accordance with many of the age-oriented papers relating to aging studied, the group 65 years of age and older was used in this study. Working within this framework, the statistics and information gathered in the study will be discussed in terms of the population 65 years of age and over. Accident Involvement Nationwide in 1968, motor vehicle accidents killed 7,477 persons 6 5 years of age and older for a death rate of 41.8 per 100,000 population. This rate was higher than for all other age groups, except the 15-24 year old age group. 29 Motor vehicle accidents ranked first among National Safety Council, An Investigation of the Problems and Opinions of Aged Drivers' (Chicago, 1968), p p . 2-3. 28 all accidental deaths for the 65-74 year old age group and second for the 75 year old and older age group.3® Most traffic accident figures were not corrected for miles driven. If this was accomplished, the senior driver age group might have a poorer traffic accident record than that which seemed apparent. A study by the National Safety Council (1969),31 in which they reported on data received from 23 states found drivers over the age of 65 were involved in only 5.7 per cent of all traffic accidents. The study further stated that when averages for each age group of senior drivers were compiled, 17 senior drivers per 100 drivers were involved in a traffic accident, while all age groups, 15-75 years and above were found to have an average rate of 25 drivers involved in a traffic accident. One might conclude that senior drivers are safer drivers when compared to other age groups. lead to a false assumption. This could National Safety Council study data was based on the number of drivers. Perhaps a better measure would be to know such things as the number of miles driven by senior drivers under varying conditions or the accessibility of automobiles to the senior driver in relation to the number of accidents. 30 National Safety Council, Accident Facts 1969 (Chicago, 1969), p. 8. 31Ibid., p. 54. 29 Judge Sherman G. Pineallver 32 in a atudy of 30 states and the District of Columbia collected information relative to the accident involvement of senior drivers and based on the percentage of the senior driving population over 65 years of age. The study indicated that in those states sampled senior drivers had less than their share of automobile accidents in proportion to their total number in the driving population. The study revealed that wherein senior drivers were involved in fatal accidents, certain problems associated with the driving task seemed to be reoccurring. It was interesting to note that of his findings on accident involvement for senior drivers in 31 jurisdictions, the state of Michigan placed twenty-third and that the senior driver in this state had the highest fatal accident involvement index of any age group. 33 Alfred Crancer's study in the State of Washington also found the senior driver's involvement ratio in all accidents was lower than other age groups with a comparable sex distribution. However, the senior driver in Washington was involved in a higher percentage of fatal accidents than would be expected on the basis of his representation in the driving population. 32 Sherman G. Finesilver, The Older Driver. A Statistical Evaluation of Licensing ana Accident Involve­ ment in 30 States {Denver, 1^69). 33 Alfred Crancer, Involvement of the Problem Driver in Fatal Motor Vehicle Accidents, Research Report No.' 0B2' (dlympiaT'I^fiTr---------------- 30 Evidence concerning the decrease or increase in rate of involvement in accidents varies according to what rates are used. Senior driver studies have also compared the senior driver age group with other age groups in relation to automobile accidents. Studies seemed to show a U-shaped relation between age and accident involvement. That is, there was a high accident frequency for the 34 young driver and the senior driver. Solomon in a large sample studied a series of accidents which occurred during a given period on 600 miles of different sections of main rural highways in eleven different states, and calculated accident involvement rates for different classes of individuals. He described accidents through detailed observation and documentation of a sample of drivers operating on the same roads. His study showed great variation in accident involvement rate as a function of age. Involvement rates of the under 25 year old age groups were approximately two times as high as the middle age groups. The older age group (over 65) also showed a higher involvement rate. 34 D . Solomon, Accidents on Main Rural Highways Relate to Speed, Driver and Vehicle (Washington, 1964) . 31 With respect to age differences and accident rates, Solomon's findings were consistent with other 35 36 studies by McFarland, Tune, Welford and Baker. 37 McFarland refers to a study conducted in Germany (Munsch, 1966) where the comparison of age versus experi­ ence was possible due to a sufficiently large portion of the population not beginning to drive until older age. Munsch's study found accidents were more frequent during the first three years of driving experience regardless of the age at which driving was begun. In a study conducted in France 38 correlation between age of the driver and the age of the license indicated the female group accounted for more new licenses at older ages and that the aged female new driver group had a poorer accident record than was expected. 35 R. A. McFarland, G. S. Tune and A. T. Welford, "On the Driving of Automobiles by Older People," Journal of Gerontology, Vol. 19 (April, 1964), 190-197. 36 J. S. Baker, "Evaluating the Older Driver," Traffic Digest and Review (March, 1965), 23-25, 30. 37 R. A. McFarland, "Psychological and Behavioral Aspects of Automobile Accidents," Traffic Safety Research Review, Vol. 12, No. 3 (September, 1968) , 71-80. 38 F. Leygue, P. Duflot and F. Hoffmann, "Investi­ gation into the Influence on Accidents of the Driver, His Driving Experience and the Age and Power of the Vehicle," International Road Traffic Safety Review, Vol. 14, No. 1 (1965), 13-22.---- --------- ------- 32 When considering the involvement of the 65 year old and older age group in automobile accidents, an additional point should be made regarding their involvement in fatal accidents. In a study by Markush 39 data indicated that since 1900, the motor vehicle mortality rates for individuals 65 years and over were higher than for any other age group, when based on 100,000 population. Markush presented data for the period 1906 to 1964, and in every case the mortality rate for this group was much greater than for other groups despite a generally decreasing trend which began in 194 5. As numerous writers have already suggested, the fact that drivers of certain ages exhibited higher accident probabilities does not mean that age in itself was the direct causal factor, but rather that age was associated with other parameters which were more directly causal. The transition of traffic record keeping from manual to electronic data processing procedures has rendered detailed and specific comparisons of the type of accidents and violations associated with various age groups. Recent tabulations suggest that the types of accidents in which senior drivers become involved, differ from the types of accidents associated with lower age 39 R. E. Markush, J. Clark, R. Leibel, C. Adams and B. Ryterband, "Motor Vehicle Accidents in the United States (1906-1964)," The Journal of the American Medical Association, Vol. 203, No. 2 (1968), 3-fcl. 33 groups. McFarland, et a l . (1964) restated by McFarland 40 in regard to the type of accident by age, suggested that older drivers show an increasing degree of failure to perceive adequately or react quickly enough; they exhibited a gradual loss of ability to cope with the normal hazards presented by an increasingly demanding traffic environment. 41 In a National Safety Council study, Planele reported the senior driver did not always perceive his driving problems at the appropriate level of importance in relation to accident occurrence. The senior driver's accident problems involved interaction with the traffic flow around him rather than his ability to maintain him­ self within the flow of his own lane. His chief problems seemed to emerge in the driving operations of changing lanes, turning, passing and backing. The senior driver was also prone to problems of inattention and was guilty of running stop signs and red traffic signals. An early study on California drivers by Earl 42 Allgaier, found three driving faults to be more prevalent among senior drivers. These were failure to yield right of way, improper turning and disregard of 4(1 41 McFarland, et a l ., 190-197. National Safety Council, An Investigation, p. 3. 42 Earl Allgaier, "Accident Involvement of Senior Drivers," Traffic Digest and Review (March, 1965). 34 signals. Other studies seemed to indicate the same 43 44 areas (McFarland, Tune, Welford, and Baker). In a University of California study, 45 on driving behavior it was reported that generally the senior driver age group showed behavior which was associated with cautiousness, slower speed, fewer speed changes and more and longer brake use. Data from the Virginia Traffic Crash Facts 46 showed that for the age groups 65 years and over, the problem of not yielding the right of way exceeded the next most common fault, following too closely, by 100 per cent. The senior driver tended to be involved in multiple 47 vehicle accidents. When they were involved xn single vehicle accidents, the causes most often cited were drowsiness, faulty driving, adverse driving conditions, and medical problems. The consequences of involvements also showed dif­ ferences between ages. Senior drivers seemed to have less 43McFarland, et al., 190-197. 44 Baker, p. 30. 45 University of California, Driving Ability as Affected by Age# Institute of Transportation and Traffic Engineering (September 30, 1968). 46 Virginia State Police Department, Virginia Traffic Crash Facts, 1966 (Richmond, 1966, pp. 46-4$’. 47 H. S. Penn, Causes and Characteristics of Single Car Accidents: Part , highway Research Record No. 79 (Washington, 196^), pp. 1-8. 35 serious accidents than younger drivers, although the picture was confused by the fact that older people took longer to recover from injuries and such injuries as they 48 sustained were more likely to be fatal. The overall indicator is the paradoxical one that senior drivers are cautious but nevertheless have a fairly high accident rate. Summary In this chapter a review of literature has been presented and considered to be relevant to this investiga­ tion concerning the senior driver. The senior citizen population has increased and trends indicate that this age group will continue to grow for years to come. In the state of Michigan one-half of the senior citizen population resided in four of Michigan's 66 counties. Wayne. They included Genessee, Macomb, Oakland, and As the senior citizen population increased so did the driving population for this age group. More and more people who reached age 65 each year find themselves in a society in which the automobile has become an integral way of life. drivers. As a result there are more and more senior The increase in senior drivers was lessened somewhat by the indication that as one became older he began to drive less. 4fi McFarland, e t a l ., pp. 190-197. 36 Presently, male senior drivers out number female senior drivers and the difference becomes greater as age increases even though women generally outlive men. For the most part, past studies dealing with the senior driver have used chronological age as a criteria, however, the literature reveals that environmental condi­ tions affect age and in as much as age is a multidimen­ sional variable, there is a need to look at more than one aspect of the problem. Motor vehicle accidents ranked first among acci­ dental deaths for the 65-74 year old age group and second for the 75 year old and older age group. Studies relative to the senior driver differed depending on what criteria were used. Some investigations showed that senior drivers had less than their share of automobile accidents in pro­ portion to their percentage of the driving population. Other studies which compared the senior driver with other age groups, showed the senior driver to have a high accident involvement rate, second only to that of the younger driver. With respect to fatal accident involve­ ment, the studies agreed that the senior driver had a higher rate of involvement. According to the literature it can be further concluded that the senior driver is a very cautious person and drives at a slower speed. Their driving faults seem to be in the area of yielding and turning. CHAPTER III PROCEDURE Population and Sample The population from which the sample for this study was selected, consisted of those senior drivers whose names and driving records were recorded in the Michigan Department of State, Driver and Vehicle Services (driver licensing file). All driving records were in alphabetical order on 100 computer reels, accounting for 5,000,000 (million) drivers. When the sample was determined, the Driver and Vehicle Services division was completing the final phase of placing all Michigan drivers on computer reels. In selecting one reel from which to secure a sample of senior drivers, there was no reason to believe that the driving performances or the proportion of senior drivers was any different for the sample computer reel selected or any other reel which might have been randomly selected from the total 100 reels. The senior driver population was estimated to be 49 9.5 per cent of the total Michigan driving population. 49 Michigan Department of State, Michigan Driver Statistics Report No. 1, Driver and Vehicle Services, July 21", 1 « 8 . --------37 38 It was determined that the senior driving population for Michigan would amount to 475,000 drivers or 9.5 per cent of 5,000,000 drivers. Each computer reel would contain approximately 4,750 senior drivers with expired and non­ expired driver licenses. To facilitate the study, each reel was considered a cluster of heterogeneous drivers in the state of Michigan. One reel, No. 43, was randomly selected to represent the driving population for the study. Because of a busy time schedule followed by the Michigan Department of State and the constant use of Michigan driver records for official purposes, the pro­ gramming and computer time was done at Michigan State University Computer Services. The selected reel, No. 43, from a Burroughs Computer, type 550,7 track, 800 density, was converted by the Department of State in order for it to be read at the Michigan State University Computer Center's IBM Computer, type 3600, 7 track, 556 density. Distribution of the Sample Michigan senior drivers numbering 4,280 on the selected heterogeneous reel were removed and put onto a separate reel. Licenses were considered expired if not renewed during 1968 and before. There were 924 senior driver records removed from the reel due to license expiration. Sixteen additional driving records were removed due to incomplete record data. 39 The total number of records used was 3,340. Three thousand and fifty-nine non-expired senior driving records were categorized by the computer as to zip code residency, sex, and age group to determine the representation of the sample for the state of Michigan. Two hundred and eighty- one additional non-expired records had no zip code and were recorded manually. Table 2 presents the distribution of the 3,340 Michigan senior drivers used in this study. Each of the 3,340 senior drivers had a valid driver's license. The year 1969 was established as a reference base from which to determine the senior driver's age. Urban and rural residency was determined according to the zip code of the senior driver's address. The total number of male senior drivers outnumbered by almost two to one the female senior drivers. This closely conforms to the Michigan Depart­ ment of State study on the distribution of Michigan - . 50 drivers. Methods of Processing the Data The 3,340 senior driver records were originally in alphabetical order by last name from the Department of State. The 3,340 records were then put in numerical order by zip code area with those records without zip 50Michigan Department of State, Driver Statistics. 40 TABLE 2.— Distribution of 3,340 senior driver records. Item N Drivers Per Cent of Drivers Age Group 65-69 1462 43.77 70-74 1011 30.27 75-79 609 18.23 80-84 207 6.19 85-89 48 1.44 90-94 2 .06 95-99 1 .03 TOTAL 3340 99.99 Male 2207 66.07 Female 1133 33.92 TOTAL 3340 99.99 Urban 1612 48.26 Rural 1728 51.73 TOTAL 3340 99.99 Sex Residency N a Number 41 codes recorded first, followed by the records with zip codes 48001 through 49999. A computer readout sheet was obtained containing all 3,340 records on each senior driver's residency, sex, age, and accident record. Due to the fact that Michigan State University programmers had difficulty in inter­ preting a Burroughs tape on an IBM computer, further pro­ gramming of the senior driver reel was unsuccessful. All remaining data was derived manually from the computer readout sheet containing the 3,340 senior driver records. Determining the Sample for Analysis ~ Only those senior driver records indicating an accident involvement were used. A total of 611 Michigan senior drivers with an accident record was read and recorded. Table 3 presents the distribution of the 611 Michigan senior drivers who had an accident record at age 65 years or older. As previously stated, the year 1969 was used as a basis to determine the senior driver's age. Their previous driving record before age 65 was not considered. The total number of male senior drivers with an accident record outnumbered female senior drivers with an accident record. The table further shows an even distribution of urban senior drivers versus rural senior drivers. 42 TABLE 3.— Distribution of 611 senior drivers with an accident age 65 or older. Item N Drivers Per Cent of Drivers Age Group 65-69 156 25.53 70-74 239 39.11 75-79 160 26.18 80-84 38 6.22 85-89 17 2.78 90-94 1 .16 95-99 __ 0 TOTAL 611 99.98 Male 470 76.92 Female 141 23.07 TOTAL 611 99.99 Urban 314 51.39 Rural 297 48.60 TOTAL 611 99.99 0 Sex Residency N = Number 43 Age groups.--Ages were grouped at five year intervals beginning with age 65 years and ending with 99 years of age. Each senior driver's age at the time of the accident was determined and those who had an accident at age 65 years or older were recorded. The last two age groups were dropped from final analysis due to null data. Sex.— Each driving record was recorded by male or female. Urban and rural residency.— Residency was deter­ mined according to the zip code of the senior driver's address. Zip code areas were considered urban in the state of Michigan according to the 1960 United States Census 51 maps of urbanized areas and the United States 52 Numerical List of Post Offices by Zip Codes. In order to determine zip code districts for the state of Michigan, it was necessary to chart the zip codes on a Michigan Highway Map. All zip code numbers have five digits and each digit signifies a location. For example, the zip code number 48823 with the digit 4 at the beginning of the zip code refers to a nation-wide area including Michigan, Ohio, Indiana and Kentucky. These states have zip codes which begin with a 4. ®^United States Department of Commerce, 1960 Census, pp. 24, 29, 34. 52United States Post Office, United States Numberical List of Post Offices by Zip C o d e , obtained from local Post Office. 44 The second digit, 8, refers to a particular state, in this case Michigan. Michigan also uses the number 9. Any zip code which begins with 48 or 49 pertains to only Michigan. The third digit, 8, in combination with the first two digits (e.g., 488) refers to a postal district. By charting on a map, the cities with a 4 88 zip code it was possible to find the district's perimeter. This was done for all districts 480 through 499 as shown in Figure 5. The last two digits, 23, as in our example, refer to a particular city. In this case 2 3 was Bast Lansing. This information was tabulated manually as a zip code district map was not available. To further define urban areas, detailed maps were obtained from the Bureau of the Census. The maps showed cities and surrounding urbanized areas. These cities and areas were determined from the United States Post Office Numerical List by Zip Code and their zip code numbers were recorded. The darkened regions on Figure 5 show the approximate size and location of urban areas for the state of Michigan. The detailed maps from the Bureau of the Census are included in the Appendices. Table 4 shows the distribution of senior drivers with an accident record by zip code area. The table shows a further breakdown of urban and rural senior drivers by zip code area. This reveals a good balance of urban Figure 5.— Zip code districts in the State of Michigan. 46 TABLE 4.- -Distribution of senior drivers with accident records by zip code. Zip Code District Total Drivers Urban Drivers Rural Drivers 480— 58 43 15 481— 65 51 14 482— 102 102 0 *483— 0 0 0 484— 11 1 10 485— 14 14 0 486— 8 3 5 487— 14 5 9 488 — 37 3 34 489— 15 15 0 490— 67 12 55 491— 7 7 0 492— 22 9 13 493— 17 0 17 494— 54 28 26 495— 21 21 0 496— 21 0 21 497 — 22 0 22 498 — 45 0 45 499— 11 ___ 0 11 611 314 297 TOTAL *Expansion number for Detroit 47 and rural drivers as well as a comparative number of drivers in relation to the population distribution. All zip code districts in the state of Michigan for both urban and rural areas were accounted for in the study. Violation factors.— Those causal factors listed on the accident record indicating a cited or non-cited accident involvement as recorded by the investigating officer were used. The codes used in this study were derived from the Michigan Department of State and Michigan Department of State Police Traffic Records. Cited accident code.— Cited accident code was the following: VI V2 V3 V4 V5 V6 V7 V8 V9 VI0 Vll VI2 VXI » =» « = = = = = = = a = a Speed too fast Failed to yield right of way Drove left of center Improper overtaking Passed stop sign Disregarded traffic signal Followed too closely Made improper turn Improper or No signal Improper parking location Other improper driving No violation indicated Under the influence of alcohol Since accident code Vll (Other improper driving) was rather nebulous, it was necessary to do further investi­ gation of these accidents. Only accident records from 1968 and 1969 were available from the Michigan Department of State Police Accident File, the original source of the Michigan Department of State driver licensing files. 48 Accident record data for those drivers with a Vll cited accident for the years 1968 and 1969, including the driver's name, accident report number, city or county police department and date of the accident were manually recorded from the computer readout sheet and obtained from the microfilm file. The descriptive written report from the investigating officer was recorded and categorized. Code V12 (No violation indicated) was deleted from the final analysis due to an absence of data. Non-cited accident c o d e .— Non-cited accident code was the following: XI X2 X3 X4 X5 X6 « = = = = = Under the influence of alcohol Not under the influence Influence not known Had not been drinking Not known if drinking Chemical Test given These items X2 through X6, were grouped together under X4 for the purposes of this study due to null data of these codes. Cited for under the influence of alcohol.--VX1 data results for cited accidents were recorded. There was no data recorded for XI non-cited accidents. Season.— The seasons were recorded according to the month during which the accident occurred. The twelve months were divided as fol l o w s : Winter ** December Spring = March (12) , January (3), April (1) , February (4), May (5) (2) 49 Summer « June (6) , July (7), August (8) Fall = September (9), October (10) , November (11). Vehicles involved in accidents.— Vehicles involved were recorded as one vehicle involved and two or more vehicles involved. Fatalities in accidents.— Fatalities were recorded by number and totalled for each accident. Processing the Data Michigan driving records were kept on file for a period of only six years. Therefore, it was not possible to obtain the prior accident record of those senior drivers in the older age groups when they were 65 years of age. For this reason the per cents were based upon each age group, sex, and urban and rural residency rather than the total sample. All data was recorded on columnar sheets by age group, sex, urban and rural residency. Each senior driver's age at the time of the accident was determined and those drivers who had had an accident at age 65 or above were recorded in the age group in which the accident occurred. As indicated in Table 4, there were 611 drivers who had accidents. Since there were drivers who had more than one accident during the six year period mentioned above, their inclusion is in more than one age group. Thus the total number of drivers was 664 as shown in Chapter IV, Table 5. In so far as this chapter considers procedures employed in 50 the study, mention is made of this process here and will again be noted in Chapter IV. Each type of information, i.e., per cent of senior drivers, per cent of accidents, under the influence of alcohol, per cent of accidents involving one and two or more vehicles, per cent of fatalities, and season in which accidents occurred were further grouped on these sheets. Methods for De Analyzing A descriptive analysis was made of the following data categorized by age group, sex, and residency: 1. The per cent of senior drivers involved in one and two or more accidents. 2. The per cent of cited and non-cited accidents among senior drivers. 3. The violation factors in accidents among senior The number of cited and non-cited accidents drivers. 4. among senior drivers where under the influence of alcohol was a factor. 5. The per cent of cited and non-cited accidents among senior drivers involving one and two or more vehicles. 6. The violation factors in accidents among senior drivers involving one and two or more vehicles. 51 7. The per cent of fatalities in cited and non- cited accidents among senior drivers. 8. The number of fatalities in cited accidents among senior drivers by violation factors. 9. The per cent of accidents by season among senior drivers. Summary In this chapter the methods of procedure for this investigation were presented. of obtaining the sample, driver sample, Included were (1) methods (2) distribution of the senior (3) methods of processing the data, and (4) methods for descriptively analyzing the data. CHAPTER IV THE FINDINGS The previous chapter contained the procedures and methodology used in this study. This chapter presents the findings of the investigation. It was the purpose of this study to determine whether senior drivers' accident record data would differ when categorized by age group, sex, urban and rural residency. Information concerning the age, sex, residency and accident record on 3,340 senior drivers was obtained from the Michigan State University IBM computer. Each senior driver1s age at the time of the accident was then determined manually and those who had an accident at age 65 years or older were tallied. A total of 611 Michigan senior drivers were found to have had an accident at age 65 years or older. Accident data on 611 Michigan senior drivers was tabulated and placed onto columnar sheets. Where possible, percentages were computed or obtained to illustrate the findings. 52 53 Single and Multiple Accident Involvement Among Senior Drivers' To determine the accident involvement among Michigan senior drivers the following question was raised and programmed: 1. Does the per cent of senior drivers involved in one accident and two or more accidents differ when categorized by age group, sex, urban and rural residency? Table 5 shows the breakdown of senior drivers in relation to the age group in which they had their accidents. Among the 611 drivers studied, there were drivers who had accidents in more than one age group during a six year period, thus the total number of drivers is 664. Those senior drivers in the 65-69 year age group were involved in the highest per cent of accidents. The senior drivers involved in an accident decreased from 49.55 per cent for the 65-69 year age group to 1.21 per cent for the 85-89 year age group. Male senior drivers had a 77.41 per cent involve­ ment in accidents and female senior drivers had a 22.59 per cent involvement. There was a more even distribution of senior drivers involved in an accident when classified according to urban and rural residency. Urban senior drivers had a 50.75 per cent involvement and rural senior drivers had a 49.24 per cent. Table 5 further shows that all categories had a higher per cent of senior drivers with a single accident TABLE 5.— Senior drivers involved in accidents by age group, sex , and residency. Total Drivers Per cent Drivers 65-69 70-74 75-79 80-84 85-89 329 202 96 29 8 49.55 30.42 14.45 4.36 1.21 277 167 78 24 6 84.19 82.67 81.25 82.75 75.00 TOTAL 664 99.99 552 83.13* Hale Female 514 150 77.41 22.59 418 134 81.32 89.33 TOTAL 664 100.00 552 83.13* Urban Rural 337 327 50.75 49.24 284 268 84.27 81.95 TOTAL 664 99.99 552 83.13* Item Drivers in 1 Accident Per cent 1 Acc. Drivers in 2+ Acc Per cent 2+ Acc Age Group 52 35 18 5 2 112 15.81 17.33 18.75 17.24 25.00 16.86* Sex 96 16 18.67 10.66 112 16.86 53 59 15.72 18.04 Residency KEY: * - Average Acc = Accidents 112 16.86* 55 involvement than senior drivers with multiple accidents. The 65-69 year age group had the highest per cent of drivers, 84.19, with one accident during that age span. When categorized by sex, females had a higher per cent, 89.33, of senior drivers with one accident than male senior drivers with 81.32 per cent. When categorized by residency, 84.27 per cent of the urban senior drivers and 81.95 per cent of the rural senior drivers were involved in a single accident. Cited and Non-cited Accidents Among Senior Drivers The following question was raised and programmed in order to ascertain the extent of cited and non-cited accident involvement among Michigan senior drivers: 2. Does the per cent of accidents, cited and non-cited, among senior drivers differ when categorized by age group, sex, urban and rural residency? The total number of accidents for 611 Michigan senior drivers was 812 or 1.33 accidents per driver with an accident record. Table 6 shows that the majority of these accidents, 50.12 per cent, occurred when drivers were within the 65-69 year old age group. The 407 accidents in which the 65-69 year old drivers were involved were more than all other age groups combined. Table 6 further shows that when categorized by sex, the Michigan male senior drivers had a higher per cent, 78.20, of total accidents than the female senior TABLE 6.— Accidents, cited and non-cited, by age group, sex, and residency. Total N Acc Item Per cent Acc N Cited Per cent Cited N Noncited Per cent Non-cited Age Group 65-69 70-74 75-79 80-84 85-89 407 237 119 37 12 50.12 29.19 14.65 4.56 1.47 221 138 71 23 7 54.29 58.22 59.66 62.16 58.33 186 99 48 14 5 45.70 41.77 40.33 37.84 41.66 TOTAL 812 99.99 460 56.65* 352 43.34* Ul Sex Oi Male Female 635 177 78.20 21.79 352 108 55.43 61.02 283 69 44.56 38.98 TOTAL 812 99.99 460 56.65* 352 43.34* Urban Rural 423 389 52.09 47.90 244 216 57.68 55.52 179 173 42.32 44.47 TOTAL 812 99.99 460 56.65* 352 43.34* Residency KEY: N = Number Acc - Accident * = Average 57 drivers, 21.79 per cent. When categorized by residency the urban senior drivers had a higher per cent, 52.09, of total accidents than the rural senior drivers, 47.90 per cent. In Table 6 the per cent of cited accidents among Michigan senior drivers as reported by investigating officers is shown. Michigan senior drivers were cited with being at fault according to the investigating officer in 460 or 56.65 per cent of the 812 senior driver accidents. All age categories were more often cited as being at fault. The 80-84 year old drivers were cited in 62.16 per cent of the accidents. This was a high for all age groups. When categorized by sex, the female senior drivers were cited in 61.02 per cent of their accidents, while their male counterparts were cited in 55.43 per cent of the accidents. Urban and rural residency showed an even distribution of senior driver cited accidents as there was a difference of less than 3 percentage points between each. Violation Factors in Cited Accidents Among Senior Drivers' The following question was programmed in order to determine the violation factors in cited accidents among Michigan senior drivers: 3. Do the violation factors in cited accidents among senior drivers differ when categorized by age group, sex, urban and rural residency? 58 Tables 7 and 8 show that when senior drivers are grouped according to age, sex, and residency, the two violation factors reported most often by the investigating officers were "failed to yield the right of way" and "other improper driving." After study of the accident report forms in the Michigan State Police Accident Microfilm File of the citation for "other improper driving," it was found that the two most common driving errors leading to this citation were: (1) "improper backing," and the assured clear distance ahead." (2) "failed to stop in All "other improper driving" factors were too few in number to be relevant. When categorized by residency, "failed to yield the right of way" and "improper turn" were the two viola­ tion factors in which the rural senior driver exceeded the urban senior driver. Cited for Under the Influence of Alcohol in Accidents Among Senior Drivers To determine if the influence of alcohol was a factor in accidents among Michigan senior drivers, the following question was raised and programmed: 4. Does under the influence of alcohol become a factor in accidents among senior drivers when categorized by age group, sex, urban and rural residency? Tables 7 and 8 show that when categorized by age group, sex, and residency that in only eight of the 812 TABLE 7.— Violation factors in cited accidents by age group. VI V2 V3 V4 V5 V6 V7 V8 V9 V10 Vll 65-69 22 77 14 11 4 5 13 19 1 1 70-74 7 43 6 8 1 3 10 12 1 75-79 4 22 1 1 3 2 5 7 80-84 3 5 0 1 0 0 1 85-89 0 4 0 0 1 0 36 151 21 21 9 10 Item Total vx: 54 221 5 2 45 138 2 0 1 25 71 1 1 0 0 12 23 0 0 1 0 0 1 7 0 29 40 2 4 137 460 8 Age Group TOTAL Key: VI V2 V3 V4 V5 V6 V7 * * = = = * Speed too fast Failed to yield right ofway Drove left of center Improper overtaking Passed stop sign Disregarded traffic signal Followed too closely V8 V9 V10 Vll VXl Made improper turn Improper or no signal Improper parking location Other improper driving Under the influence of alcohol, cited accident. TABLE 8.— Violation factors in cited accidents by sex and residency. Item VI V2 V3 V4 V5 V6 V7 V8 V9 V10 Vll Total XVI 29 120 16 15 6 5 25 30 2 2 102 352 8 7 31 5 6 3 5 4 10 0 2 35 108 0 36 151 21 21 9 10 29 40 2 4 137 460 8 Urban 17 69 14 14 5 6 22 16 1 2 78 244 3 Rural 19 82 7 7 4 4 7 24 1 2 59 216 5 TOTAL 36 151 21 21 9 10 29 40 2 4 137 460 8 Sex Male Female TOTAL isidency Key: VI V2 V3 V4 V5 V6 V7 = = = = = = - Speed too fast Failed to yield right ofway Drove left of center Improper overtaking Passed stop sign Disregarded traffic signal Followed too closely V8 V9 V10 Vll XVI = = ® = = Hade improper turn Improper or No signal Improper parking location Other improper driving Under the influence of alcohol, cited accident. 61 accidents studied were the senior drivers cited as being "under the influence of alcohol." Drivers in the 65-69 year age group were cited as being "under the influence of alcohol" in five of the eight accidents. When categorized by sex, male senior drivers were cited as being "under the influence of alcohol" in the eight accidents. When categorized by residency, rural senior drivers were cited as being "under the influence of alcohol" in five accidents and the urban senior driver in three accidents. Cited and Non-cited Accidents Involving flne and Two or More Vehicles Among Senior Drivers The following question was programmed in order to ascertain the extent of cited and non-cited accidents among Michigan senior drivers involving one vehicle and two or more vehicles: 5. Does the per cent of accidents, cited and non-cited, among senior drivers involving one vehicle and two or more vehicles differ when categorized by age group, sex, urban and rural residency? Table 9 shows when categorized by age group, sex, urban and rural residency all categories had a higher per cent of accidents involving two or more vehicles. For all age groups, more than 91 per cent of the accidents involved two or more vehicles. TABLE 9.— Vehicle involvement by age group, sex, and residency. Total N Acc Per cent Acc N Acc 1 Veh Per cent Acc 1 Veh N Acc 2 Veh Per cent Acc 2 Veh 65-69 70-74 75-79 80-84 85-89 407 237 119 37 12 50.12 29.19 14.65 4.56 1.47 33 19 8 3 1 8.12 8.01 6.72 8.11 8.33 374 218 111 34 11 91.88 91.98 93.27 91.89 91.66 TOTAL 812 99.99 64 7.88* 748 92.11* Age Group Sex Male Female 635 177 78.20 21.79 48 16 7.56 9.04 587 161 92.44 90.96 TOTAL 812 99.99 64 7.88* 748 92.11* Urban Rural 423 389 42.09 47.90 25 39 5.91 10.02 398 350 94.08 89.97 TOTAL 812 99.99 64 7.88* 748 92.11* Residency KEY: N Acc Veh * = = = Number Accidents Vehicles Average 63 When categorized by sex and residency both had more than 89 per cent of their accidents involving two or more vehicles. Violation Factors in Cited Accidents involving One and Two or More Vehicles Among Senior Drivers The following question was programmed in order to determine the violation factors among Michigan senior drivers in cited accidents involving one vehicle and two or more vehicles: 6. Do the violation factors among senior drivers in cited accidents involving one vehicle and two or more vehicles differ when categorized by age group, sex, urban and rural residency? Table 10 shows that when categorized by age group, sex, and residency the two violation factors reported most often by investigating officers for drivers cited in accidents involving one vehicle were "speed too fast" and "other improper driving" (failed to stop in the assured clear distance ahead). Rural senior drivers were cited more often for "speed too fast" in one vehicle accidents than were urban senior drivers. Table 11 shows that when categorized by age group, sex, and residency the violation factors reported most often by investigating officers for drivers cited in accidents involving two or more vehicles were "failed to yield right of way" and "other improper driving" to stop in the assured clear distance ahead). (failed TABLE 10.— Violation factors in cited accidents involving one vehicle by age group, sex, and residency. VI Item V2 V3 V4 V5 V6 V7 V8 V9 V10 Vll Total Age Group 65-69 70-74 75-79 80-84 85-89 7 3 1 1 TOTAL 12 1 1 1 1 0 1 1 0 1 0 1 0 0 3 4 1 1 12 8 3 2 0 9 25 5 4 17 8 9 25 3 6 6 19 9 25 Sex Male Female 1 9 3 12 TOTAL 1 1 1 0 1 1 0 1 0 1 0 0 Residency 2 10 Urban Rural 12 TOTAL KEY: vl V2 V3 V4 V5 V6 = = = = = 1 0 1 1 1 1 Speed too fast Failed to yield right ofway Drove left of center Improper overtaking Passed stop sign Disregarded traffic signal 1 0 1 V7 V8 V9 V10 VI1 0 1 0 0 = Followed too closely = Made improper turn - Improper or No signal = Improper parking location = Other improper driving TABLE 11.— Violation factors in cited accidents involving two or more vehicles by age group, sex, and residency. Item VI V2 V3 V4 V5 V6 V7 V8 V9 V10 Vll Total 65-69 70-74 75-79 80-84 85-89 15 4 3 2 77 43 22 5 4 14 5 1 10 8 1 1 4 1 3 5 3 1 13 11 4 1 18 12 7 1 1 1 1 1 2 1 51 41 11 1 209 131 67 21 7 TOTAL 24 151 20 20 9 9 29 39 2 4 128 435 Male Female 20 4 120 31 15 5 15 5 6 25 4 29 10 2 2 2 O ". 3 4 5 31 335 IT TOTAL 24 151 20 20 9 9 29 39 2 4 128 435 Urban Rural 15 9 69 82 14 6 14 6 5 4 6 3 22 7 15 24 1 1 2 2 76 52 239 197 TOTAL 24 151 20 20 9 9 29 39 2 4 128 435 Age Group 1 Sex Residency KEY: VI V2 V3 V4 V5 V6 = = = = = = Speed too fast Failed to yield right of way Drove left of center Improper overtaking Passed stop sign Disregarded traffic signal V7 V8 V9 VI0 Vll = = = = = Followed too closely Made improper turn Improper or No signal Improper parking location Other improper driving 66 When categorized by residency, "failed to yield right of way" and "improper turn" were the two violation factors in which rural senior drivers exceeded urban senior drivers in cited accidents involving two or more vehicles. Fatalities in Cited and Non-cited Accidents Among Senior Driver's To determine the extent of fatalities in cited and non-cited accidents among Michigan senior drivers, the following question was raised and programmed: 7. Does the per cent of fatalities in accidents, cited and non-cited, among senior drivers differ when categorized by age group, sex, urban and rural residency? Table 12 shows Michigan senior drivers had a high per cent of fatalities in accidents. There were 446 fatalities or 54.92 per cent occurring in 812 accidents. When categorized by age group, there were 262 fatalities or 65.17 per cent when drivers were within the 65-69 year old age group. This figure was higher than any other senior driver age group. The table further shows a breakdown of the fatalities into cited and non-cited accidents. The table reveals that 60.76 per cent of the fatalities occurred when the senior drivers were cited with being at fault by the investigating officer and 39.23 per cent of the fatalities occurred when the senior driver was not at fault. TABLE 12.-— Fatalities in cited and non-cited accidents by age group • Item Total N Acc Per cent Acc Total Fatal Per cent Fatal. per T Acc N Fatal in Cited Acc Per cent Fatal. Cited Acc per T Fatal. N Fatal in Noncited Acc Per cent Fatal. Non-cited Acc per T Fatal. Age Group 65-69 407 50.12 262 65.17 158 60.31 104 39.69 70-74 237 29.19 120 50.63 71 59.16 49 40.83 75-79 119 14.65 42 35.29 26 61.90 16 38.09 80-84 37 4.56 16 43.24 11 68.75 5 31.25 85-89 12 1.47 6 50.00 5 83.33 1 16.66 812 99.99 446 TOTAL KEY: N = Number Fatal. = Fatalities T = Total Acc = Accidents * = Average 54.92* 271 60.76* 175 39.23* 68 Table 13 shows when categorized by sex, male senior drivers had a higher per cent of fatalities in accidents than did female senior drivers. A fatality occurred in 56.37 per cent of accidents in which male senior drivers were involved and 4 9.71 per cent of the accidents in which female senior drivers were involved. Urban and rural residency showed an even distribution of fatalities in senior driver accidents. The table further shows a breakdown of the fatalities into cited and non-cited accidents. The table reveals that 70.45 per cent of the fatalities occurred when the female senior drivers were cited with being at fault by the investigating officer and 58.37 per cent for the male senior drivers. A 65.89 per cent of the fatalities occurred when rural senior drivers were cited with being at fault by investigating officers and 55.89 per cent for the urban senior drivers. Violation Factors in Cited Accidents Involving Fatalities Among Senior Drivers The following question was programmed in order to determine the violation factors among Michigan senior drivers in cited accidents involving fatalities: TABLE 13.— Fatalities in cited and non-cited accidents by sex and residency. T 6 Total N Acc Per cent Acc Total Fatal Per cent Fatal. per T Acc N Fatal. in Cited Acc Per cent Fatal. Cited Acc per T Fatal. N Fatal in Noncited Acc Per cent Fatal. Non-cited Acc per T Fatal. Sex Male Female 635 177 78.20 21.79 358 88 56.37 49.71 209 62 58.37 70.45 149 26 41.62 29.54 TOTAL 812 99.99 446 54.92* 271 60.76* 175 39.23* Urban Rural 423 389 52.09 47.90 229 217 54.13 55.78 128 143 55.89 65.89 101 74 44.10 34.10 TOTAL 812 99.99 446 54.92* 271 60.76* 175 39.23* Residency Key: N = Number Fatal. * Fatalities T = Total Acc = Accidents * = Average 70 8. Do the violation factors in senior driver cited accidents involving fatalities differ when categorized by age group, sex, urban and rural residency? Table 14 shows that when categorized by age group, sex, and residency the violation factor reported most often by investigating officers in cited accidents in which fatalities were involved was "failed to yield the right of way." Cited and Non-cited Accidents Season Among Senior Drivers The following question was raised and programmed in order to ascertain the extent of cited and non-cited accidents among Michigan senior drivers: 9. Does the per cent of senior driver accidents, cited and non-cited, by season differ when categorized by age group, sex, urban and rural residency? Table 15 shows Michigan senior drivers were involved more frequently in accidents during the winter season. The table further reveals that 28.20 per cent of the accidents occurred during the winter season. However, when categorized by age group, the 80-84 and 85-89 year old drivers were an exception. Data indicated that these age groups had 40 per cent of their accidents during the spring season. Table 16 shows that when categorized by sex, Michigan male senior drivers had the highest per cent, 28.34, of their accidents in the winter season, and the TABLE 14.— Fatalities per violation factor by age group, sex, and residency. V10 Vll 2 28 15 5 5 1 158 71 26 11 5 1 2 54 271 21 6 1 2 42 12 209 62 14 27 1 2 54 271 2 3 8 6 11 16 1 2 36 18 128 143 5 14 27 1 2 54 271 VI V2 V3 V4 V5 V6 V7 V8 65-69 70-74 75-79 80-84 85-89 22 7 3 1 64 24 13 5 2 5 3 8 1 5 3 1 2 4 9 1 18 8 TOTAL 33 108 8 9 10 5 14 27 Male Female 21 12 84 24 8 5 4 8 2 3 2 14 TOTAL 33 108 8 9 10 5 Urban Rural 16 17 44 64 2 6 4 5 5 5 TOTAL 33 108 8 9 10 Item V9 Total Age Group 3 1 1 1 Sex Residency KEY: VI V2 V3 V4 V5 V6 * = * = = = Speed too fast Failed to yield right ofway Drove left of center Improper overtaking Passed stop sign Disregarded traffic signal V7 V8 V9 VI0 Vll * Followed too closely = Made improper turn = Improper or No signal = Improper parking location « Other improper driving TABLE 15.— Accidents per season by age group. Winter Spring Summer Fall Total Acc Per cent Acc 65-69 407 50.12 117 28.74 88 21.62 92 22.60 110 27.03 70-74 237 29.19 67 28.27 49 20.67 57 24.05 65 27.00 75-79 119 14.65 34 28.57 22 18.49 31 26.05 32 26.89 80-84 37 4.56 8 21.62 15 40.54 6 16.22 8 21.62 85-89 12 1.47 3 25.00 5 41.66 3 25.00 1 8.33 TOTAL 812 99.99 229 Item N Acc Per cent Acc per T Acc N Acc Per cent Acc per T Acc N Acc Per cent Acc per T Acc N Acc Per cent Acc per T Acc Age Group KEY: Acc = Accidents N = Number T = Total * = Average 28.20* 179 22.04* 189 23.27* 215 26.47* TABLE 16.— Accidents per season by sex and residency. Winter Item Total Acc Per cent Acc N Acc Spring Summer Per cent Acc per T Acc N Acc Per cent Acc per T Acc N Acc Per cent Acc per T Acc Fall N Acc Per cent Acc per T Acc Sex Male 635 78.20 180 28.34 138 21.74 154 24.25 163 25.66 Female 177 21.79 49 27.68 41 23.16 35 19.77 52 29.37 TOTAL 812 99.99 229 28.20* Urban 423 52.09 118 27.89 Rural 389 47.90 111 28.53 TOTAL 812 99.99 229 28.20* 22.04* 189 23.27* 215 26.47* 21.51 100 23.64 114 26.95 88 22.62 89 22.87 101 25.96 179 22.04* 23.27* 215 26.47* 179 Residency KEY: Acc - Accidents N = Number T = Total * = Average 91 189 74 lowest per cent, 21.74, in the spring. The Michigan female senior drivers had the highest per cent, 29.37, of their accidents in the fall season and the lowest per cent, 19.77, in the summer. When categorized by residency, urban senior drivers had 27.89 per cent of their accidents in the winter season, while rural senior drivers had a 28.53 per cent rate. Summary This chapter presented the major findings of the study. These findings included a descriptive comparison of Michigan senior drivers' accident records when cate­ gorized by age group, sex, urban and rural residency. The following chapter contains the summary, conclusions, and recommendations of the study. CHAPTER V SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS This chapter contains a brief statement of: (1) the problem, method of procedure and major findings, (2) conclusions based on the findings, and, (3) recommendations (4) recommendations for further research. Summary Statement of the Problem It was the purpose of this study to determine whether the accident records of Michigan senior drivers differed when categorized by age group, sex, urban and rural residency. The study proposed to derive data in order to answer the following programmed questions: 1. Does the per cent of senior drivers involved in one accident and two or more accidents differ when categorized by age group, sex, urban and rural residency? 2. Does the per cent of accidents, cited and non-cited, among senior drivers differ when categorized by age group, sex, urban and rural residency? 3. Do the violation factors in cited accidents among senior drivers differ when categorized by age group, sex, urban and rural residency? 75 76 4. Does under the influence of alcohol become a factor in accidents among senior drivers when categorized by age group, sex, urban and rural residency? 5. Does the per cent of accidents, cited and non-cited, among senior drivers involving one vehicle and two or more vehicles differ when categorized by age group, sex, urban and rural residency? 6. Do the violation factors among senior drivers in cited accidents involving one vehicle and two or more vehicles differ when categorized by age group, sex, urban and rural residency? 7. Does the per cent of fatalities in accidents, cited and non-cited, among senior drivers differ when categorized by age group, sex, urban and rural residency? 8. Do the violation factors in senior driver cited accidents involving fatalities differ when categorized by age group, sex, urban and rural residency? 9. Does the per cent of senior driver accidents, cited and non-cited, by season differ when categorized by age group, sex, urban and rural residency? The Methods of Procedure The population from which the sample for this study was selected consisted of those senior drivers whose names and driving records were recorded in the Michigan Department of State, Driver and Vehicle Services. All driving records were in alphabetical order on 100 computer reels, accounting for 5,000,000 (million) drivers. Each computer reel was considered a cluster of heterogeneous drivers in the state of Michigan. There was no reason to believe that the driving performances or the proportion 77 of senior drivers was any different for the sample computer reel selected or any other reel which might have been selected from the total 100 reels. One reel, Number 43, was randomly selected for the study. The information on the selected reel came from a Burroughs Computer, type 550, 7 track, 800 density and was converted by the State Department in order for the information to be read by the Michigan State University Computer Center's IBM Computer, type 3600, 7 track, 556 density. A computer readout sheet was obtained containing 3,340 driving records on each senior driver's residency, sex, age and accident record. Only those senior driver records indicating an accident involvement were used. A total of 611 Michigan senior drivers with an accident was read and recorded. Michigan driving records were kept on file for a period of only six years. Therefore, it was not possible to obtain the prior accident record of those senior drivers in the older age groups when they were 65 years of age. For this reason the per cents were based upon each age group, sex, and urban and rural residency rather than the total sample. All data was recorded on columnar sheets by age group, sex, urban and rural residency. Each senior driver's age at the time of the accident was determined 78 and those drivers who had had an accident at age 65 or above were recorded in the age group in which the accident occurred. As indicated in Table 4, there were 611 drivers who had accidents. Since there were drivers who had more than one accident during the six year period mentioned above, their inclusion is in more than one age group. Thus the total number of drivers was 664 as shown in Chapter IV, Table 5. Each type of information, i.e., per cent of senior drivers, per cent of accidents, under the influence of alcohol, per cent of accidents involving one and two or more vehicles, per cent of fatalities, and season in which accidents occurred were further grouped on these sheets. The Major Findings The following is a summary of the major findings of this study: Single and Multiple Accident jfnvolvement When categorized by age group, sex and residency, all categories had a lower average, 16.86 per cent, of senior drivers with two or more accidents compared to an average of 83.13 per cent of senior drivers with one accident. Those senior drivers in the 65-69 year age group were involved in the highest per cent of accidents. senior drivers involved in an accident decreased from The 79 49.55 per cent for the 65-69 year age group to 1.21 per cent for the 85-89 year age group. Male senior drivers had a 77.41 per cent involve­ ment in accidents and female senior drivers had a 22.59 per cent involvement. There was a more even distribution of senior drivers involved in an accident when grouped according to urban and rural residency. All categories had a higher per cent of senior drivers with a single accident involvement than senior drivers with multiple accidents. Cited and Non-cited Accidents The majority of total accidents occurred when drivers were in the 65-69 year age group. The 407 accidents, 50.12 per cent, in which the 65-69 year old drivers were involved were more than all other age groups combined. Male senior drivers had 78.20 per cent of total accidents and female senior drivers had 21.79 per cent. Urban senior drivers had a 52.09 per cent of total accidents and the rural senior drivers had 47.90 per cent. When categorized by age group, sex and residency, all categories showed Michigan senior drivers were cited with being at fault according to investigating officers in 56.65 per cent of the 812 senior driver accidents. 80 The 65-69 year age group had the highest per cent of accidents, 50.12, but the lowest per cent, 54.29, with being cited for the accident by investigating officers. The 80-84 year age group had only a 4.56 per cent of accidents but the highest per cent, 62.16, with being cited for the accident by investigating officers. The female senior drivers had a lower per cent, 21.79, of accidents than the male drivers but a higher per cent, 61.02, with being cited for the accident by investigating officers. Violation Factors in Cited Accidents When categorized by age group, sex and residency, all categories had "Failed to yield the right of way" and "other improper driving" for the two violation factors most often reported by investigating officers in cited accidents. Upon further investigation of the original accident report for "other improper driving," two predominent driving errors were found, (1) "improper backing" and (2) "failed to stop in the assured clear distance ahead." Cited for Under the Influence of Alcohol in Accidents There were eight senior drivers cited with being "under the influence of alcohol" for a total of 812 senior driver accidents. The 65-69 year old drivers were cited as being "under the influence of alcohol" in five of the 81 eight cases. All cases were male senior drivers of which five were from a rural residency. Cited and Non-cited Accidents Involving One and two or More Vehicles When categorized by age group, sex and residency, all categories had a higher per cent of accidents involving two or more vehicles among senior driver accidents. For all age groups, more than 91 per cent of the accidents involved two or more vehicles. When categorized by sex and residency, both had more than 89 per cent of their accidents involving two or more vehicles. Violation Factors in Cited Accidents Involvincj One and two or More Veflicles The violation factor among senior drivers in cited accidents involving one vehicle was "speed too fast" for all categories. The violation factors most often reported in cited accidents in which two or more vehicles were involved were "failed to yield right of way" and "failed to stop in the assured clear distance ahead." Fatalities in Cited and Non-ci’ fced Accidents When categorized by age group, sex and residency, all categories showed a high per cent, 54.92, for fatalities in senior driver accidents. 82 For total accidents, the 65-69 year old drivers had the highest involvement, 65.17 per cent, for fatali­ ties, while the 75-79 year old drivers had the lowest involvement, 35.29 per cent. In cited accidents, where the senior drivers were at fault according to investigating officers, the 85-89 year old drivers had the highest involvement, 83.33 per cent, for fatalities, while the 70-74 year old drivers had the lowest involvement, 59.16 per cent. The female senior drivers had a 70.45 per cent for fatalities in cited accidents where they were at fault according to investigating officers as compared to the male senior drivers 58.37 per cent. The rural senior drivers had a 65.89 per cent for fatalities in cited accidents where they were at fault according to investigating officers as compared to the urban senior drivers' 55.89 per cent. Violation Factors in Cited Accidents Involving Fatalities The violation factor most often reported in cited accidents where senior drivers were cited with being at fault according to investigating officers was "failed to yield right of way." 83 Cited and Non-cited Accidents by Season When categorized by age group, sex and residency, senior drivers revealed a higher involvement in accidents, 28.20 per cent, in the winter season (December, January, February). However, when categorized by age group, the 80-84 and 85-89 year old drivers were an exception. Data indicated that these age groups had 4 0 per cent of their accidents during the spring season. Conclusions The following are the conclusions based upon the findings of the study: 1. Michigan senior drivers have a slightly higher accident rate than the national senior driver rate. The findings of this study showed that 18.29 per cent of Michigan senior drivers had an accident record, while the national rate for 1969 was 17.58 per cent. 2. Data indicated senior drivers between the ages of 65-69, who were males and living in an urban area are more likely to be involved in an accident. 3. Michigan senior drivers are more likely to have only one accident during a five year age period. 4. Data showed that the majority of senior drivers when involved in an accident are cited as being at fault. 84 5. Data revealed that the majority of senior driver accidents involved a fatality. This fatality involvement increased when senior drivers were cited as being at fault. 6. Data showed the majority of senior drivers are cited as being at fault, for "failed to yield the right of way" and "failed to stop in the assured clear distance ahead." 7. Data indicated that cited for being "under the influence of alcohol" is not a major contributing factor in accidents among senior drivers. 8. Data revealed senior drivers use their auto­ mobiles throughout the year as accidents were apparent for all seasons. Recommendations On the basis of this study, the following recom­ mendations are presented: 1. Establish a state medical advisory board made up of a medical doctor, opthamologist, optomotrist, psychologist, and a gerontologist, to advise licensing authorities and senior drivers as to their physical and mental ability to drive an automobile safely. 2. Establish senior driver re-education courses to alert senior drivers as to the medical and physical problems for this age group. This course would further assist drivers with new laws, driving problems for this 85 age group and driving techniques to help alleviate the problems. 3. A self-help driving guide be made available to senior drivers as to their driving problems, and to inform them of new laws, accident probability and fatality rate. This guide would also contain helpful hints with which to assist the senior driver to be a better driver and a more competent person. 4. The state of Michigan needs to adopt a more comprehensive reporting and records system for relevant accident research and information purposes. The present design by the Department of State is set up for a policing and penal system. The information available is limited, and a more detailed account of traffic accidents concerning the driver, the automobile, and environment needs to be available for important studies and research projects. Our present driver licensing system needs addi­ tional data to be collected and recorded that would be conducive to licensing procedures, education and improve­ ment. Information regarding licensing test results in reference to the driving record should be adopted for up­ grading licensing test procedures, the driving problems relevant to age groups, and any information vital to the driving public. This would enable a more positive approach rather than a penalizing system. 86 5. If this driving record system is to contribute to our knowledge about traffic accidents, then data must be in a form that is readily available for analysis and research. This data should be in a form available to research institutions thus enabling various computer hardware systems to program and analyze it. 6. Establish renewal driver licensing examina­ tions for the purpose of alerting senior drivers to new laws and informing them as to any bad habits or problems they may have obtained. This may best be accomplished through audio-visual testing machines. 7. The state should provide senior drivers, who after consideration, voluntarily give up their driver's license or who can no longer driver for various reasons, a means to obtain other forms of transportation for the nominal cost of a driver's license and license plates. Discussion Accident Site in Relation •fco Residency There was an interest to determine where the accidents were taking place in relation to the driver's residency. A 20 per cent random sample survey of the 611 senior drivers with accident records was selected. The drivers' residencies were recorded and then categorized as urban or rural according to zip code location and the United States Bureau of Census. 87 The number of miles from the driver's residency to the accident site could not be determined as the driver licensing records indicated only the law enforcement agency involved in the reporting of the accident and not the actual site of the accident. It was also difficult to determine the exact jurisdiction of the reporting enforcement agency in regard to urban and rural areas. The Michigan senior driver's residency was listed with the law enforcement agency or State Police post and categorized as urban or rural according to zip code location. Prom this it was determined whether the acci­ dent occurred in an urban or rural area which was or was not near the location of the residency. Upon completion of this section, urban senior drivers had their accidents in urban areas and rural senior drivers had their accidents in rural areas. Only 13.9 per cent of the rural senior drivers had their accidents in urban areas and only 10.8 per cent of the urban senior drivers had their accidents in rural areas. Recommendations for Further Research The following are recommendations for further research: 1. A study should be conducted that would con­ centrate on the driving patterns of the Michigan senior driver, e.g., proportion of daylight driving time versus 88 driving at night, proportion of driving in urban and rural areas, proportion of driving in bad weather. 2. A study should be conducted that would compare senior driving records to all facets of exposure. 3. A similar study should be conducted that would compare other age groups with senior drivers to determine similarities and differences in the accident involvement. BIBLIOGRAPHY BIBLIOGRAPHY Books Dimling, J. Driver Licensing and Performance, Vol. II Survey of State Practices. Washington, E>.C.: Clearinghouse, 1968. Long, L. World Almanac and Book of Facts 1969. World Publishing Company, 1969. Cleveland: United States Department of Commerce. 1960 Census of Population. Washington, D.C.: United States Government Printing Office, 1960. _______ . 1960 Census of Population Michigan. Washington, D .d.: United States Government Printing Office, 1960. _______ . Driver Licenses 1965. Washington, D.C.: States Government Printing Office, 1965. United _______ . Population Estimates. Washington, D.C.: United States Government Printing Office, October, 1967. . Population Estimates. Washington, D.C.: United States Government Printing Office, December, 1967. United States Department of Health, Education and Welfare. The Nation and Its Older People. Washington, D.C.: United States Government Printing Office, 1961. United States Department of Transportation. Driver Licenses 1966. Washington, D .C.: United States Government Printing Office, 1966. _______ . Highway Safety Program Standards. Washington, D.C.: United States Government Printing Office, 1967. United States Post Office. United States Numerical List of Post Offices by zip Code. Washington, D . C.; United states Government Printing Office. 90 91 Publications of Organizations American Automobile Association. Age, Exposure and Accidents. Washington, D.CT1 The Association, rsrr:---Crancer, A. Involvement of the Problem Driver in Fatal Motor Vehicle Accidents. Research Report No. ?T02. Olympia: Washington Department of Motor Vehicles, Division of Research and Statistical Analysis, 1967. Department of State Police. Michigan Traffic Accident Facts 1966. Lansing: The Department, 1966. . Michigan Traffic Accident Facts 1968. The Department, 1968. Lansing: Finesilver, S. G. The Older Driver, A Statistical Evalua­ tion of Licensing and Accident Involvement in 30 States.' Denvers University of Denver, 1969. Michigan Department of State. Michigan Driver Statistics Report No. 1 . Lansing: Driver and Vehicle Services, T768. National Safety Council. Accident Facts 1969. The Council, 1969. Chicago: . An Investigation of the Problems and Opinions of Aged Drivers. Chicago: The Council, l9(>8. P e n n , H . S . Causes and Characteristics of Single Car Accidents, Part I . Highway Research Record N o . 79. Washington, D.d.: National Academy of Sciences, 1965. Solomon, D. Accidents on Main Rural Highways Relate to S p e e d T Driver and Vehicle. Washington, D . C . : United States Department of Commerce, 1964. University of California. Driving Ability as Affected by A g e . Los Angeles: Institute of Transportation and Traffic Engineering, 1968. University of Michigan and Wayne State University. Michigan Facts on A g i n g . Report 2. Ann A r b o r : Institute of Gerontology, 1967, Virginia State Police Department. Virginia Traffic Crash Facts 1966. Richmond: The Department, 19&6. 92 Periodicals Algaier, G. "Accident Involvement of Senior Drivers." Traffic Digest and Review, 1965, p. 3. Baker, J. S. "Evaluating the Older Driver." Traffic Digest and Review, Vol. 3 (1965), 23-25, 30. Beadenkopf, W. G . , e t a l . "An Epidemiological Approach to Traffic Accidents." Public Health Reports, Vol. 71 (1965), 15-24. Birren, J. E. "Research on the Psychological Aspects of Aging." Geriatrics, Vol. 18 (1963), 393-403. Leygue, F., et al. "Investigation into the Influence on Accidents of the Driver, His Driving Experience and the Age and Power of the Vehicle." International Road Traffic Safety Review, Vol“ 14 (1966), 13-22'.— ------------- Markush, R. E., et a l ■ "Motor Vehicle Accidents in the United States' (1906-1964)." The Journal of the American Medical Association, Vol. 203 (1968), 3 = T T . -------------------------------- Marsh, B. "Aging and Driving." Vol. 31 (1969), 12. Traffic Engineering, McFarland, R. A., et al. "On the Driving of Automobiles by Older People." Journal of Gerontology, Vol. 19 (1964), 190-197. McFarland, R. A. "Psychological and Behavioral Aspects of Automobile Accidents." Traffic Safety Research Review, Vol. 12 (1968), 71-So. Swartz, F. "Aging 1968." (1968), 591-596. Michigan Medicine, Vol. 67 APPENDICES APPENDIX A 94 APPENDIX A DEPARTMENT OF STATE DATA PROCESSING DIVISION BURROUGHS Magnetic Tape Layout Record Description: Field Rec. Count Char. Count 3 Header Record I d e n t License Number 1 13 Name (con't) Last) License ]Cnfor T I P E 0 Issue y s r xy ry date P s o P m b i g e Birthdate Name (First, Middle, * 1 1 1 2 6 6 City Street 19 36 3T Record.Description; T Rec. Date of Count d Accident e n t 3 1 6 2 Accident Accident V i k Report Number e n i h 3 1 1 1 2 S t a t e Zip Code 1 5 Police Department Coded Items 24 | I | 3 13 12 12 1i *2 S e X * 1 i I Exam Stat. Sample Accident Record Printed on Computer Readout Sheet 176BJ1234567892311R 706310026708U02JOHN THOMAS JONATHON 123456 EAST MICHIGAN ST KALAMAZOO 14904 4M3901 072S021569020201654321KALAMAZOO PD V2 X4 P5 681031 1 (> Posting Date APPENDIX B Number <»f Inluliiunii URDANIZHD ARFAS— MICHIGAN I'lyftloulh Salem |An n A rboj Ib Ay ciT 5A GIN A W Ann Arbor S u p e rio r $Af C « n to n B a n ao r rssexviLU ANN ARBOR Monitor H am pt fPSILAN Van B oren lAKfifti'VHM p tt u f ie id P o rtsm o u th % YpsllantJ (ini' BCLlfVJUt Frankeniust PAY CO York — I--- """ Augusta ’ f ~£ti?r*pt<;r sagI naw co K o c h v il le --------Zilwauk C h e s te r mm] B u e n a Vista [G R A N D R A P f j * v Jrn n a f ROCHFOfl T n e tn rd Forest iw o ij n t F lushing Monms M ount M orris r ''?t -& FLUSHING wwfr T aH m adga '/.■jfsti'.'1. -ZiL-, FUNr?*??*/* J *'•-'s&s W*# C la y to n G rand Rapid ? GRAND RAPIDS MPIPHf B urton *«£**&•''V* :• J D a v la o n ^ ^ G a in e s 1 Moody Grand Blanc Galnee SCBBttpM Argentina Fenton Growtond 98 M k Ih ^ . io URBANIZED AREAS— MICHIGAN [jACKSONl «'"* Ik a l a m a / o o j | ti -H----------------1 mwtt | C onper lAHiMwrNt rJ UMckntitii Kninmmoo Il ANSINGI Richland O e W itt f C o m fito c h — ft**+*** ***> INGH if L(Him si KALAMAZOO: / ..vZ'M* MUJUMNOO tt "/. EASfLAhMNl .LANSING IA( INS O N W'i D e lta I L a m in g Pavilion 1 wtsjfiAxr rilAMON' » N a p n le u ’ Summit AUSriNJlAXE Windsor> Delhi LitH’ iIv P r a ir ie R o n d o C o l t J r i i l tii i S c h o o lc r a f t KALAMAZOO CO W CK SO N CO [ S A G I N AWI S K l i t i ( ) N ' M U S K l i t I O N ....[ E I G H T S ] Kochvllla T lttab aw aa j L a k c to n Z ilw a u k a a ! M u sk eg o n 5®* / i p* Saginaw MltfftfGHN L r MUSKEGON \ rMUSKEGON ~% S f MUSI* ROObLVELl HEIGHTS j IPARK SJWWK rUB u e n a V ista SAGINAW afrVfc. F ru ltp o rt Norton Milct COMPONI NTS l i t U H F lA N I/tD AREA ! Irtcorpor.llerl P t e c n U niiK noor.itm l U rban PlacM I ... I 01 bar U n in co rp o rated A rea s. bovsrnm knt Spaulding BOUNDARY SYMB015 ------ — Internationet Line — Stale lin e ------------- - County tine — — — — Minor Civil or Censut County Diviwon Line r a iN T iN t o p p i e i t i s o t — m n t/ii May* e b n io s teenier!** I* 4 n U I n m l l a U c M « M ea m « a tt the Ban** DETROIT URBANIZED AREA MOjsan (AKE3RJCN In d e p e n d e n c e Washington O akland AMtSTON W/s ,LAhiaMjCLUS MaccmD ROCHESTER PONTIAC^ l t :c a kF W f i & s . K 4 \ : ^ 0 - f ^ b ^ rv Haf^'SCn C!;rtcn Sterling ■■ W nt Bloomfield ** * • /■ *. /* ■Si-VtNGrAV ^ •?///'/,/,//>/,/. f>w > . ' / / / >t ' * ' /. *J. BEVERLY 4 m • r^ROSEvlUC , NGHAJWi Farmington WARREN VILLAGE QUAKER SOUTHFIELD BERKLEYS / • ■ ; « * •v.HUNT1 NGT0N^«, : . , ST CUMR ;5HCRE5 S&*^%WCOOS PLEASANT :-fR '0 G E r&AK PARK* CENTERLINE; EAST DETROIT P hAZEL OAKLAND C O WAYNE CO . i— Northville hSatwn g # « s^cssi tOODS ROSSE PCINTE SHORES P C IN T t f « W S Noftfwlle “iwoiyc* N y r r o u th t. neater / :E.TqoiT !*'' V tL Dearborn 1GARDEN CITY'-".; K%r^v. ^,;DEa^e4 '■ ''f.tyHKSTEH^i f& *WU ALLf N p ap * LINCOLN awn CuttWMUf JTVANOOTTI l>piKumu Romulus Huron Sum pter TRENTON FLATROCK □ BRALTER Ash CULETOH i 100 Ntintfarr «>f Inhabitants V anBuran APPENDIX C 101 APPENDIX C ZIP CODE AREAS CONSIDERED URBAN IN THE STATE OF MICHIGAN 48008-48012 48120-48129 48439 48015-48017 48134 48458-48459 48921 48136 48473-48474 48024-48026 48138 48501-48509 48030 48141-48142 48601-48609 48033-48034 48146-48156 48706-48710 48043-48046 48167-48148 48823-48826 48050-48059 48170-48173 48901-48933 48066-48073 48179 49001-49009 48075-48078 48183-48188 49201-49219 48080-48084 48192 49418 48088-48093 48197 49440-49445 48096 48201-48242 49501-49511 48101-48109 48300 102 APPENDIX D 103 APPENDIX D COMPUTER CODE LIST MICHIGAN DEPARTMENT OF STATE POLICE POSTS Location No. Location No East Lansing Brighton Ionia Ithaca Detroit Romeo St. Clair Warren Flat Rock Ypsilanti Pontiac Erie Bay City East Tawas Bad Axe Sandusky Flint West Branch Bridgeport Lapeer Jackson Clinton Tekonsha Blissfield Jonesville Battle Creek Paw Paw White Pigeon Nile New Buffalo 11 12 13 14 21 22 23 24 25 26 27 28 31 32 33 34 35 36 37 38 41 42 43 44 45 46 51 52 53 54 South Haven Wayland Rockford Reed City Mt. Pleasant Grand Haven Newaygo Hart Traverse City Cheboygan Gaylord Alpena Houghton Lake Cadillac Manistee Petoskey Marquette Newberry St. Ignace Manistique Gladstone Iron Mountain Wakefield L'anse Stephenson Calumet Munising Iron River Sault S t e . Marie 55 56 61 62 63 64 65 66 71 72 73 74 75 76 77 78 81 82 83 84 85 86 87 88 89 90 91 92 104 93