Appendices 3, C, D, E. Duane F. Dun1 ap Leonard Segel. Frederick L. Preston Peter Cool ey Barbara C. Brown. November 1976

Transcription

1 UM-HSR Contract Number DOT-HS A METHODOLOGY FOR DETERMNNG THE ROLE OF VEHCLE HANDLNG N ACCDENT CAUSATON Appendices 3, C, D, E Duane F. Dun1 ap Leonard Segel. Frederick L. Preston Peter Cool ey Barbara C. Brown November 1976

2 Prepared for the Department of Transportation, National Highway Traffic Safety Administration under Contract Number DOT-HS The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the National Highway Traffic Safety Administration.

3 Tochnicol Report D~cumtotion Page ' 1. Rrport no. UM-HSR Gor*rnmmt Acc*ssvon No. 4. 7~11..nd krbt~tl* 5. Repoet Dole A METHODOLOGY FOR DETERMNNG THE ROLE OF VEHCLE November 1976 HANDLNG N ACCDENT CAUSATON Appendices B, C, D, E 7. *U*O,JS) D.F. Dunlap, L. Segel, F.L. Preston, P. Cooley, B.C. Brown 9. P*rfonn~n~ Orgmuzo~~on Name md Addr*ss Highway Safety Research nstitute The University of Michigan Huron Parkway & Baxter Road Arbor. Michigan &nsortng Apmncy Na. end Addrmsr National Highway Trafflc Safety Admini strati on U. S. Department of Transportation Washington, D.C. 259 S. Suppl*~tay Hot*s 8. P*rforn~ng Organ~zot~on Raport No. 1 UM-HSR Wok Unit No (TRAS) 11. Controct or Grant No. DOT-HS Type of Report ond P*rtod Covered Final / Abstract A review of the literature on the role of vehicle handling in accident causation skjhs that there P,a; keen mucn c?njezture regarding the link between vehicle nandlinl and accidents. Little of a defensible nature is?>parent other than vehicle size seers to correlate with accident excerience. An exazination OF arai labie mass accident data also shcws this apparent size effect as,well as sow correlations betdeen (1),tehicle tracn width and rollo~er accidents, (2) driver ase and size of car, (3) size of car and accide~ts on curves, and (4) driver age and accidents on curves. For purposes of the present study, hy'potheses were developed linking venicle handling characteristics to acciden: sejcriptors. Careful consideration is then given todards developing a statistical analysis vethod that kould serve to su?:ort or negate s~ch hypor~eses and which would further deiine tke asojnt of data required to siipport a given hypothesis. ssl~entation of tb,e ne:hodoloqy :o investigate the role of vehicle handling, as 'roposea, re~uires that four kinds of data be collected: ex3osure-to-risk dbta, accident cats, vehicle handling descriptors, ar,d "ira~e risk" data. The require-ent for each of these data catec:ries is discussed at length. ;n addition to defining an accident data collection and analysis -e:hcdology, efforts were also devoted towards advaqcing the present state of the art in reconstructing :he pre-crash phase of accidents an: towards outlining a deteninistic dnalysis procedure for relating vehicie handling performance di rec:ly to accident avoidance perfor~ance. The conclusions eophasize the forxidatrle and costly nature of implementing the pro~csed ~e:ho@ola?j, but point up :qat by dovetailing efforts with o:ner areas (of cor,cern to accident causation analysis) agencies could substantially increase the bencfit/cost ratio of follow-on research and ir~leventation. Accident Reconstruction, Vehicle Hand1 ing, Statistical Analysis, Skid Marks, Vehicle Parameter Data, Accident Data 19. kcvd* Cl...if. (of 61s r- NONE Form DOT F 17.7 (8-72) B. kwrity Cmmnil. (of * prg.1 NONE 18. ~ ~ ~ Stotnont ~, b ~ ~, ~ Ropmbctim of wmpl*td pog* authorized UNLMTED 21- No. of Pog*r Puc U. S. COVt'RNMi.rST FlllMMC OFFCE : lq7j 7))-54/178

4 APPENDX B: TABLE OF CONTENTS Analysis of Mass Accident Data for Vehicle Handling Causative Factors APPENDX C: 1ndi rect Standardization - An Example APPENDX D: Supplemental Accident Report Form for Vehicle Handling APPENDX E: Supplemental Data on Re1 ationships Between Vehicle Hand1 i ng Parameters (and ndices) and Accident Descriptors

5 APPENDX B ANALYSS OF MASS ACCDENT DATA FOR VEHCLE HANDLNG CAUSATVE FACTORS This appendix consists of the detailed tables and figures from whence the broad conclusions in Section 5 were derived. The discussions are of mass accident data from King County (Seattle), Washington and from the State of Texas. Each set of accidents is from 1973 with the data from Texas representing a 5% sample of a1 1 the accidents from Texas during that year. Further, each data set was filtered to include only passenger cars, unimpaired drivers, and wet or dry surfaces. The data from King County were further restricted to contain only vehicles involved in single-vehicle accidents, or the striking vehicle in multivehicle accidents. The data from Texas consisted only of vehicles involved in si ngle-vehicl e accidents. The specific findings from each of these investigations are discussed next. B. 1 King County (Seattle), Washington Accident Data Bivariate tables of vehicle types versus several conjectured accident variables were constructed for the King County fi 1 tered data set. Two vehicle type variables were used. The vehicle make/model categories are shown in Table B.1, and the vehicle body type categories in Table B.2. Classifications of make/model s into body types are given in Tab1 e B.3. These two variables were then separately coupled with several other variables to determine their joint influences on the accident record. A listing of the tables that were constructed and an assessment of the utility of the derived information is given in Table B.4.

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8 Table 8.2. Vehicle Body Type Sub-Compact/Mi ni Sub-compact Compact ntermedi ate Standard/Ful 1 Size Luxury Sedan Personal Luxury European Sports Car Super Sports Speci a1 ty/pony

9 Table 8.3. Vehicle ::alte. -r - Code Vehicles N1C Classic, Rebel, Matador AblC Ambassador AFC American, Hornet NC Gremlin Chrys ler Dodge Coronet, Charger Dodge Polara, Yonaco Dodge Charger, Challenger Dodge Dart, Swinger Plymouth Belvedere, Satellite, GTX Plymouth Fury, Suburban Valiant, Duster Ford Fairlane, Torino, Falcon Ford Custom, Galaxie, Country Squire Thunderbird, Landau hiustang, blach 1, Grande, Boss $laverick, Futura Pinto Nercury :ilontego, Cyclone, lroyager b!ercury 3lonterey, Parklane, Narquis, Colony Park Cougar Briick Special, Skylark, Sportwagon LeSabre, Kildcat, Centurion Electra 225 t Riviera Cadillac Calais, DeVille, Brougham Chevrolet Chevelle, Nomad, Greenbrier Be1 Air, mpala, Brookwood Camaro Chevy 11, Nova, Corvair Vega Oldsmobile F-85, Cutlas?, Vista-Cruiser 88 Pontiac Tempest, GTO, Safari Catalina, Ventura, Bonneville, Granville Fircbird Toyota Corona, Crown VW Beetle Ford Capri Ope1 Kadett, 19, Ralye Austin blini, America, 13, blini Cooper

10 Table 8.4. Vehicle Type Bivariate Tables - Code - Name 49 Vehicle Make/ 21 Model 22 - Name Character of Road Road Surface Weather Light Conditions Type of Accident Vehicle Mix Vehicle Body Type Vehicle Style State of Vehicle Registration DriverVehicl e Actions Misc. Actions Major Contributing Action Vehicle Defects No, of Occupants Residence Proximity Driver Occupation Driver Sex Utility G U G U NUD NUD U MU U MU NUD NUD U U NED U MU 97 Driver Age-5 yr. G U Groups 99 Seat Belt Usage-Driver U U U 51 Vehicle Body Type Character of Road Road Surface Light Conditions Type of Acc i dent Vehicle Mix Vehicle Style State of Vehicle Registration DriverVehicle Actions Misc. Actions GU MU NUD MU MU MU NUD NED MU

11 , TableB.4. (Cont.) - - Code - Name Code 51 Vehicle Body Type Name Utility Major Contributing GU Action Vehicle Defects No. of Occupants Residence Proximity Driver Occupation Driver Sex Driver Age-5 yr. Groups Seat Be1 t Usage-Driver NUD MU MU U GU G U U KEY: NED NUD MU U GU Not Enough Data No Unusual Differences Marginal Utility Useful nformati on Great Utility

12 n addition to the vehicle type variables, some other combinations of variables were a1 so examined, independent of vehicle type. A listing of the tables constructed for these ancillary variables is given in Table B.5. n the subsections that follow, each of the variables which were coupled with the vehicle type variables are discussed separately. The ancil lary variables are discussed next. The bulk of the raw tables con- structed in the study are not included but can be made available to those interested. B.l.l Vehicle Type Variables. The two vehicle type variables are Vehicle Make/Model and Vehicle Body Type. The joint influence of these variables on the accident record is discussed as follows: Character of Road The vehicle body type categories ranked in terms of highest and lowest involvements on curved sections of road are shown in Table B.6. (MakeModel involvements on curves are given in Table 5.2 of Section 5.) t is evide.nt that those vehicles having the highest incidence of accidents on curves are the sporty and sub- compact body types. the luxury model class. The least involved vehicles are generally in These findings suggest that either smaller and sporty vehicles and/or people who drive smaller and sporty vehicles are more apt to be involved in accidents on curved sections of road. Road Surface The body type categories ranked in terms of highest and lowest involvements on wet surfaces are shown on Table B.7. Similar data for specific Make/Model categories are given on Table 5.6 of Section 5. The data do not show any consistent trends in either Body Type or MakeModel. Specific vehicle make/model s vary by as much as 113 more or less than the mean of 36% involvement in wet accidents. None, however, with more than 1 accident cases varies by more than 1/4 from the mean. While the most involved

13 Table B.5.,Ancillary Tables - Code - Name Code _C 2 1 Character of 92 Road Name Utility No, of Occupants GU Driver Occupation Driver Sex Driver Age-5 yr. Groups Seat Be1 t Usage-Driver Driver Occupation and Vehicle Body Type Driver Sex and Vehicle Body Type Seat Belt Usage and Vehicle Make/Model Seat Belt Usage and Vehicle Make/Model G U U GU GU GU G U G U GU 4 8 Year of Vehicle Driver Age-5 99, Year Groups 5 1 No. of Occupants Driver Occupation Driver Sex Driver Age-5 yr. Groups Seat Be1 t Usage-Driver Seat Belt Usage and Vehicle Body Type MU GU MU G U U G U KEY: NED NU D MU U GU Not Enough Data No Unusual Differences Marginal Uti 1 i ty Useful nformation Great Utility

14 Table B.6. Percent Accidents on Curved Sections of Road Vehicle Body Type Type European Sports Car Super Sport Sub-Compact/Mini Speci a1 ty/pony Sub-compact Compact ntermediate Standard/Full Size Personal Luxury Luxury Sedan % nvolvement (N) 3.3 (132) 22. (5) 17.7 (265) 15.9 (718) 15.3 (386) 14.5 (1,158) 11.7 (1,416) 11.2 (2,337) 1.9 (192) 1.2 (177) Total % nvolvement 13.5 (9,523) % = (1) Accidents on Curves for a Given Body Tye Total Accidents for a Given Body Type

15 Table B. 7. Percent Accidents on Wet Surfaces. Vehicle Body Type Type European Sports Cars Special ty/pony Sub-compact Personal Luxury ntermediate StandardFull Size Sub-Compact/Mi n i Sub-compact Luxury Sedan Super Sport % nvolvement (N) (132) (718) 38.1 (386) 38. (192) 36.2 (1,416) 35.3 (2,337) 35.2 (1,158) 34.3 (265) 31.1 (177) 3. (5) Total % nvolvement 35.9 (9,523),., (1) Accidents on Wet Surfaces for a Given Body Type / = Total Accidents for a Given Body Type

16 vehicle types are the European sport cars and specialtylpony types, the least involved are the super sport class. These findings do not presently suggest any clear trends toward vehicl es which are more heavily involved in wet-surface accidents. Type of Accident Forty-four types of accidents are classified in the King County data file. to vehicle hand1 ing properties: and turning col 1 is i on accidents. Of these, four types seem.to have some relevance overturning, rear-end, sideswipe, Overturning accidents are the most recognizabl e accident type that are associated with vehicle size, or more specifically, track width. The overturning potential of a vehicle is directly related to the ratio of its center-of-gravi ty height to track width. Since the center of gravity cannot be made any lower than ground clearance and passenger packaging dictates, the major factor which practically determines overturning potential is the track width, n the data shown on Table B.8, the body type categories are ranked in terms of highest and lowest involvements in overturning accidents. Data for specific Make/Model categories are given in Table 5.9 of Section 5. t is irmediately evident from Table 8.8 that the vehicles showing the highest frequency of rollover accidents are the smaller types, i.e., the ones with the narrowest track width. The implications with respect to specific values of track width and specific makes and models are discussed in Section 5. Rear-end accidents should provide some idea of the braking. performance of specific vehicles. The data for rear-end col li- sions in the filtered sample for the Seattle data are for vehicles which are the striking vehicle in two- or more-vehicle coll isions. Thus, braking performance differences should appear. Makelmodel and body type vehicle categories are ranked in terms of highest and 1 owes t i nvol vemen ts in rear-end accidents on Tables B.9 and B.lO, respectively. The two most heavily

17 Table B. 8. Percent of Overturning Accidents. Vehicle Body Type Type European Sports Car Sub-Compact/Mi ni Sub-compact Compact Special ty/pony ntermediate Standard/Full Size Luxury Sedan Personal Luxury Super Sport % nvolvement (N) 6.8 (132) 5.3 (265) 3.6 (386) 3. (1,158) 2.2 (718) 1.4 (1,416).7 (2,337).6 (177).5 (192). (5) Total % nvolvement 2.8 (9,523) % = (1) Overturning Accidents for a Given Body Type Total Accidents for a Given Body Type

18 Table B.9. Percent Rear-End Accidents Vehicle MakeModel Make/Model % nvolvement (N) Most nvolved AMC Gremlin 5 (2) AMC Ambassador 42 (43) Vega 39 (152) Oldsmobi le F-85, Cutlass, Vista-Cruiser 39 (153) Chevrol et Chevel le, Nomad, Greenbrier 38 (235) Dodge Charger, Challenger 37 (62) Fi rebi rd 37 (6) Chrysler 36 (126) Least nvol ved Maverick, Futura 22.5 (289) Buick Special, Skylark, Sportwagon 23.3 (133) Plymouth Be1 vedere, Sate1 1 i te, GTX 25.6 (156) Ford Capri 26.2 (61) Dodge Dart, Swinger 26.6 (177) AMC Arneri can, Hornet 26.9 (67) Total % nvolvement 32.6 (9,523) % = (1) Rear-End Accidents for a Given Make/Model Total Accidents for a Given Make/Model

19 Table B. 1. Percent Rear-End Accidents Vehicle Body Type Type Personal Luxury Sub- Compac t ntermediate Sub-Compact/Mi ni StandardlFull Size Luxury Sedan Special ty/pony European Sports Car Compact Super Sport % nvolvement (N) 33.9 (192) 33.2 (386) (1,416) (265) 32.3 (2,337) 32.2 (177) 31.2 (718) 31. (132) 27.1 (1,158) 16. (5) Total % nvolvement ' 32.6 (9,523) % = (1) Rear-End Accidents for a Given Body Type Total Accidents for a Given Body Type

20 involved models are' the AMC Gremlin and the AMC Ambassador--a1 bei t each has a low number of total accident involvements. Except for these two, the accident frequencies for the "Most nvolved" vehicles are not greatly higher than the rear-end involvement frequency of 32.6% for the total sample. Some of the "Least nvolved" vehicles have frequencies substantially less than the total sample; however, the Maverick has a rear-end involvement percentage of almost one-third less than that of the total sample. Sideswipe and turning coll i sion accident frequencies could indicate the presence (or lack thereof) of side visibility problems in driving a vehicle. Make/model and body type vehicle categories are ranked in terms of highest and lowest involvement frequencies on Tables B.11 and B.12, respectively, for sideswipe accidents and on Tables B.13 and B.14, respectively, for turning collision accidents. n the "Most nvolved" class, the Oldsmobile 88; Ford Capri ; and Cadi1 1 ac Calais, Devil le, Brougham show higher than total sample frequencies in both turning collision and side- swipe accidents. There are no common make/models in the "Least nvol ved" category. n the body type categories, the least involved vehicles are super sport and European sports car types. n general, however, the findings are mixed. No definite conclusions are apparent. Vehicle Mix The "Vehicle Mix" variable refers to the mix of vehicles, objects, pedestrians, etc., that were involved in the coll ision accident. At this writing, there seems to be little that can be determined from this variable relative to vehicle handling. Vehicle Body Type - Vehicle Style The "Vehicle Body Type" classifications are given on Table B. 2. The relationship between these and Vehicle Make/Model classifications is shown on Table B.3. t should be kept in mind that these c1 assificati ons were determined by General Motors Corporation as part of their original work in developing the

21 Table B.ll. Percent Sideswipe Accidents Vehicle Ma ke/model Make/Model % nvolvement (N) Most nvol ved Oldsmobi le 88 Buick Riviera Ford Capri Cougar Cadillac Calais, DeVille, Brougham AMC American, Hornet Ford Fairlane, Torino, Falcon Least nvolved VW Beetle 4.9 (41) Toyota Corona, Crown 5.2 (97) Ope1 Kadette, 19, Ralye 7.1 (56) Mercury Monterey, Parklane, Marquis 8.8 (12) AMC Classic, Rebel, Matador 9.1 (88) Buick Special, Sky1 ark, Sportwagon 1.5 (133) Plymouth Be1 vedere, Sate1 1 i te, GTX 1.9 (156) Total % nvolvement 13.4 (9,523) % = (1) Sideswipe Accidents for a Given Make/Model Total Sideswipe Accidents for a Given ~ake/~odx

22 Table 9-12, Percent Sideswipe Accidents Vehicle Body Type Type Compact Speci a1 ty/pony Personal Luxury Sub-Compact/Mi ni Sub- Compact Luxury Sedan ntermediate Standard/Ful 1 Size European Sports Car Super Sport % nvolvement (N) 14.8 (1,158) (718) (192) (265) (386) 13.6 (177) 13.5 (1,416) 8.7 (2,337) 8.3 (132) 8. (5) Total % nvolvement 13.4 (9,523) % = (1) Sideswipe Accidents for a Given Body Type Total Sideswipe Accidents for a Given Body Type

23 Table Percent Turning Collision Accidents Vehicle MakeModel Ma ke/model % nvolvement (N) Most nvol ved 1 dsmobi 1 e 88 Dodge Charger, Chall enger Cadi1 lac Calais, DeVi 1 le, Brougham Ford Capri Dodge Pol ara, Monaco Mercury Montego, Cycl one, Voyager Ford Custom, Gal axie, Country Squi re Maverick, Futura Least nvolved Buick Riviera 2. (5) Thunderbi rd, Landau 2.9 (14) Camaro 3. (135) Oldsmobile F-85, Cutlass, Vista Cruiser 3.3 (153) Fi rebi rd 3.3 (6) Vega 3.9 (152) Dodge Coronet, Charger 4.1 (123) Total % nvolvement 6.2 (9,523) % = (1) Turning Collision Accidents for a Given Make/Model Total Accidents for a ~iten Make/Model

24 Table Percent Turning Coll ision Accidents Vehicle Body Type Type Luxury Sedan StandardFul 1 Size Compact ntemedi ate Special ty/pony Sub- Compact Sub-Compact/Mi ni Personal Luxury Super Sport European Sports Car % nvolvements (N) 1.2 (177) 6.8 (2,337) 6.6 (1,158) 6.3 (2,337) 5.71 (718) 5.7 (386) 5.3 (265) 4.2 (192) 4. (5) 3. (132) Total % nvolvement / = (1) Turning Collision Accidents for a Given Body Type Total Accidents for a Given Body Type

25 Coll ision Performance and njury Report (CPR) form. classifications may not be the best for vehicle handling studies. n future work, it seems evident that more refined classes of vehicles will have to be developed. The distribution of accident frequencies of makehodel classes as a function of body style is not shown here due to the bulkiness of the table. An indication of the variability of body types within a given make/model classification can be obtained from Table B.15. This table shows the highest and lowest percentages of accidents involving station wagons among the 1 isted make/rnodel s. t is evident that some make/model classes are more homogeneous than others. is apparent. The Again, the need for more refined classes of vehicles Contributing Actions Actions contributing to an accident are divided into Miscellaneous Actions and Major Contributing Actions in the Seattle data file. Among the miscellaneous actions, skidding accidents provide the most information with respect to vehicle hand1 ing considerations. The highest and 1 owest percentages of skidding accidents for the make/rnodel and body type variables are shown on Tables B.16 and B.17, respectively. t is evident that the super sport and sub-compact/mini type vehicles are the most involved in skidding accidents, while the least involved are the intermediate and luxury models. An exception in the least involved category is the Vega. Major contributing actions include speeding, fol lowing too close, failure to yield, and inattention. The highest and lowest percentages of accidents involving speeding for make/model and body type categories are shown on Tables B.18 and B.19, respectively. Not unexpectedly, the highest involvement in speeding accidents are among the super sport, European sports car, and specialty/ pony classes. Somewhat of a surprise, however, is that the leading makehodel in speeding accidents is the VW Beetle. Further, it

26 Table B. 15. percent Accidents nvolving Station Wagons Among Ma ke/model Cl asses. Make/Model % nvolvement (N) Most Station Wagons AMC Classic, Rebel, Matador 3 (88) AMC Ambassador 26 (43) Plymouth Fury, Suburban 23 (182) Vega 23 (145) Oldsmobile F-85, Cutlass, Vista Cruiser 23 (15) Mercury Monterey, Park1 ane, Marquis 22 (1) Pinto 22 (24) Least Stati on Wagons Mustang, Mach 1, Grande, Boss. (314) Thunderbi rd, Landau,O (11) Buick LeSabre, Wildcat, Centurion. (95) Cougar. (89) Cadillac Calais, DeVille, Brougham. (78) Dodge Charger, Chal 1 enger. (61) Total % nvolvement 13.6 (9,122) % = (1) Station Wagon Accidents Within a Given Make/Model Class Total Accidents for a GE~ Make/Model

27 Table B.16. Percent Skidding Accidents Vehicle Make/Model Make/Model % nvolvement (N) Most nvol ved VW Beetle Fi rebi rd Camaro Cougar Val i ant, Duster Ope1 Kadette, 19, Ralye Mustang, Mach 1, Grande, Boss Least nvolved Dodge Pol ara, Monaco 13.4 (82) Cadi 11 ac Calais, DeVi 1 ley Brougham 17.9 (78) Buick LeSabre, Wildcat, Centurion 18.8 (96) Dodge Charger, Ch a1 1 enger 19.4 (62) Vega 2.4 (152) Chrys 1 er 2.6 (126) Total % nvolvement 28.1 (9,523) % = (1) Skidding Accidents for a Given Make/Model Total Accidents for a Given Make/iilodel

28 Table B. 17. Percent Skidding Accidents Vehicle Body Type Type Super Sport Sub-Compact/Mi ni European Sport Car Special ty/pony Compact Personal Luxury Sub-compact StandardFul 1 Size ntermediate Luxury Sedan % nvolvement (N) 38. (5) 34.7 (265) 33.3 (132) 32.6 (718) 29. (1,158) 27.6 (192) 26.5 (386) 26.1 (2,337) 25.8 (1,416) 2.3 (177) Total % nvolvement % = (1) Skidding Accidents for a Given Body Type Total Accidents for a Given Body Type

29 Table B. 18. Percent Speedi ng Accidents Vehi cl e Ma ke/model Ma ke/model % nvolvement (N) Most nvol ved VW Beetle Plymouth Belvedere, Sate1 1 i te, GTX Camaro Firebi rd Ope1 Kadette, 19, Ralye Toyota Corona, Crown AMC Classic, Rebel, Matador Least nvol ved Oldsmobile (58) Cadi 11 ac Cal ai s, DeVi 11 e, Brougham 16.7 (78) Bui ck Ri vi era 18. (5) Chrysler 18.3 (126) AMC Ambassador 18.6 (43) Dodge Pol ara, Monaco 19.5 (82) Dodge Charger, Challenger 21.O (62) Total % nvolvement 26.8 (9,523) % = (1) Speeding Accidents for a Given Make/Model Total Accidents for a Given Make/Model

30 Tab1 e B, 19. Percent Speeding Accidents Vehicle Body Type Lype Super Sport European Sports Car Speci a1 ty/pony Sub-Cornpact/Mi ni Compact ntermediate Standard/Ful 1 Size Sub-compact Personal Luxury Luxury Sedan % nvolvement (N) 44. (5) 36.4 (132) 3.5 (718) 3.2 (265) 28.7 (1,158) 27.3 (1,416) 26.1 (2,337) 23.6 (386) 22.9 (192) 2.3 (177) Total % nvolvement 26.8 (9,523) % = (1) Speeding Accidents for a Given Body Type Total Accidents for a Given Body Type

31 is interesting to note that four of the make/models most involved in skidding accidents are also most involved in speed- ing accidents-vw Beetle, Firebird, Camaro, and Ope1. The least invol ved vehicles i n speeding accidents are the luxury models. The trends in fol lowi ng-too-close accidents are not clear. Tables for the mo'st and least involved make/models and body types are given on Tables B.2 and B.21, respectively. t is evident that the over-involved body types are not much more involved than the mean involvement, and that the specific over-involved make/ model types represent a mixture of vehicle classes. Fail ure-to-yield and inattenti on accidents are the most conlmon accidents with luxury vehicles. The most and least involved make/models and body types for failure-to-yield accidents are given on Tables B.22 and B.23, respectively. Similar data for inattention accidents are given on Tables B. 24 and might speculate that a soft ride quality could be a factor in both inattenti on and fai lure-to-yield accidents. One On the other hand, since luxury vehicles are least involved in speeding and following- too-close accidents, it is necessary that the kind of accidents such vehicles - are involved in show up more heavily in other areas. (Again, the percentages shown are based on the total number of accidents of a particular vehicle or class. Thus, if 1% of a vehicle's accidents involve speeding, the other 9% must be allocated to other kinds of accidents. The percentages given, therefore, do not give an absolute picture as to how the accident experience of a particular vehicle compares with other vehicles. Rather, the picture is that of the distribution of the accidents. within a particular vehicle class. All manner of exposure data would be required to arrive at specific conslusions regarding the absolute accident experience of a particular vehicle. Specific conclusions about the lulling qualities of a soft ride toward precipitating inattention and fai 1 ure-to-yield accidents should, therefore, be held in abeyance.)

32 Table B.2.,Percent Fol lowing-too-close Accidents Vehicle Make/Model Ma ke/model % nvolvement (N) Most nvol ved Cadi1 1 ac Cal ais, DeVi 11 e, Brougham 15.4 (78) Cougar 13.5 (89) Plymouth Fury, Suburban 13. (185) Ford Fai rl ane, Torino, Fa1 con 12.4 (274) Dodge Coronet, Charger 12.2 (123) Chrysler 11.9 (126) Least nvolved Dodge Pol ara, Monaco 1.2 (82) Mercury Montego, Cyclone, Voyager 1.9 (52) Bui ck Special, Sky1 ark, Sportwagon 3. (133) Buick Electra (55) Plymouth Belvedere, Sate1 1 i te, GTX 4.5 (156) Thunderbi rd, Landau 4.8 (14) Total % nvolvement 8. (9,523) % = (1 ) Fol 1 owi ng-too-cl ose Accidents for a Given Make/Model Total Accidents for a-~i ven Make/Model

33 Table Percent Fol lowi ng-too-close Accidents Vehicle Body Type Type Sub-compact StandardFull Size ntermediate Luxury Sedan Compact European Sports Car Speci a1 ty/pony Personal Luxury Super Sport % nvolvement (N) 8.8 (386) 8;7 (265) 8.6 (2,337) 8.47 (1,416) 8.47 (177) 7.6 (1,158) 7.58 (132) 6.7 (718) 5.2 (192). (5) Total % nvolvement 8. (9,523) % = (1) Fol lowing-too-close Accidents for a Given Body Type Total Accidents for a Given Body Type

34 Table B. 22. Percent Fail ure-to-yield Accidents Vehicle Make/Model Make/Model % nvolvernent (N) Most nvolved Thunderbi rd, Landau Cadillac Calais, Devil le, Brougham AMC Ambassador Ope1 Kadette, 19, Ralye Dodge Pol ara, lilonaco Buick Riviera Dodge Dart, Swinger Cougar Least nvol ved AMC An~eri can, Hornet Ford Capri Fi rebi rd AMC Classic, Rebel, Matador Plymouth Belvedere, Satellite, GTX Mercury Montego, Cyclone, Voyager Total % nvolvement 6. (9,523) % = (1 ) Fai 1 ure-to-y i el d Accidents for a Given Ma ke/model Total Accidents for a Given Make/Model--

35 Table B.23. Percent Failure-To-Y ield Accidents Vehicle Body Type Type Persona1 Luxury Luxury Sedan Standard/Full Si ze Compact ntermediate Sub-compact Speci a1 ty/pony Sub-Compact/Mi ni Super Sport European Sports Car % nvolvement (N) 11.5 (192) 9.6 (177) 6.3 (2,337) 6.1 (1,158) 5.72 (1,416) 5.7 (386) 5.2 (718) 4.2 (265) 4. (5) 3. (132) Total X nvolvement 6. (9,523) % = (1) Failure-To-Yield Accidents for a Given Body Type Total Accidents for a Given Body Type

36 Table B. 24. Percent nattention Accidents Vehicle Make/Model Ma ke/model % nvolvement (N) Most nvolved Thunderbi rd, Landau 11.5 (14) Ford Capri 11.5 (61) Buick Electra (55) Chrysl er 1.3 (126) Cadillac Calais, DeVille, Brougham 1.3 (78) Mercury Monterey, Park1 ane., Marquis 9.8 (12) Least nvol ved Fi rebi rd 1.7 (6) 1 dsrnobi 1 e (58) Buick LeSabre, Wi 1 dcat, Centurion 2.1 (96) Pontiac Tempest, GTO, Safari 3.4 (178) Val iant, Duster 3.7 (188) Chevrol et Chevel le, Nomad, Greenbrier 3.8 (235) Total % nvolvement 5.9 (9,523) % = (1) nattention Accidents for a Given MakeModel Total Accidents for a Given MakeModel

37 Table Percent nattention Accidents Vehicle Body Type Type Luxury Sedan Personal Luxury European Sports Car Sub-Compact/Mi ni Compact Super Sport Standard/Full Size % nvolvement (N) 1.2 (177) 8.3 (192) 7.6 (132) 6.4 (265) 6.2 (1,158) 6. (5) 5.99 (2,337) Speci a1 ty/pony Su b-compact ntermediate Total % nvolvement 5.9 (9,523),, (1) nattention Accidents for a Given Body Type /D = Total Accidents for a Given Body Type

38 Number of Occu~ants The number of occupants in a vehicle can affect both the handling qualities of the vehicle and the attention level of the driver. The highest and lowest percentages of accidents with just one occupant, in the vehicle (the driver) are shown on Tables B.26 and B.27, respectively, for make/model and body type classifications. Vehicles having the most accidents with just one occupant are comprised of a mixture of luxury and sub-compact vehicles. Vehicles having the least accident frequencies with just one occupant (i.e., vehicles most frequently involved in accidents with more than one occupant) are the convertible and super sport classes. Significantly, the one vehicle having the lowest frequency of accidents with just one occupant, or the highest frequency with more than one occupant, is the VW Beetle. This finding might suggest a load-related hand1 ing problem with the VW. Later findings will show, however, that the VW is primarily driven by younger students and skilled workers in the Seattle area, so that the load-rela ted factors seemingly apparent here must be tempered with exposure considerations (e. g., as. a matter of course, is the VW Beetle more frequently driven with more than one occupant in the vehicle than are other vehicles in the Seattle area?). Somewhat surprising (a1 though perhaps not completely unexpected) is the finding that luxury models and station wagons-relatively larger vehicles--are some of the most involved vehicles in accidents with just one occupant. Residence Proximity Conceivably, residence proximity has a bearing on accident causation through the familiarity of the driver with the local roads. Makehodel and body type classes for the most and least involved vehicles in accidents within 15 miles of the driver's residence are given on Tables B.28 and B.29, respectively. The findings in terms of specific make/model classes show a maximum

39 Table 8-26, Percent Accidents With Just One Occupant. Vehicle Make/Model Make/Model % nvolvement (N) Most One Occupant Ford Capri Chevy 11, Nova, Corvair Ope1 Kadette, 19, Rayle Buick Electra 225 Ford Fai rl ane, Tori no, Fa1 con AMC Ambassador Thunderbi rd, Landau Least One Occupant VW Beetle 65.9 (41) AMC American, Hornet 71.7 (67) Pontiac Catalina, Ventura, Bonneville 75.4 (232) Plymouth Fury, Suburban 76.2 (185) Plymouth Be1 vedere, Sate1 1 i te, GTX 76.3 (156) Plymouth Valiant, Duster 76.6 (188) Buick Special, Sky1 ark, Sportwagon 76.7 (133) Total % nvolvement 8.6 (9,523) % = (1) Accidents with Just One Occupant for a Given - MakelModel ~o=l Accidents for a Given MakeModel

40 Table B.27. Percent Accidents With Just One Occupant. Vehicle Body Type _Type Personal Luxury Sub- Compact Luxury Sedan Speci a1 tylpony Sub-Compact/Mi ni European Sports Car ntermediate Compact StandardFul 1 Size Super Sport % nvolvenient (N) 83.3 (192) 82.1 (386) 81.4 (177) 8.9 (718) 8.8 (265) 8.3 (132) 79.6 (1,416) 79.4 (1,158) 78.7 (2,337) 74. (5) Total % nvolvement % = (1) Accidents With Just One Occupant for a Given Body Type Total Accidents for. a Given Body Type

41 Table B.28. Percent Accidents Within 15 Miles of Residence. Vehi cl e Ma ke/model MakeModel % nvolvement (N) Most nvolved AMC Classic, Rebel, Matador Dodge Pol ara, Monaco VW Beetle 1 dsmobi 1 e 88 Buick Special, Sky1 ark, Sportwagon Cadi 11 ac Cal ai s, DeVi 11 e, Brougham AMC Ambassador AMC American, Hornet Least nvol ved Buick Riviera 8. (5) Ford Capri 85.3 (61) Buick Electra (55) Thunderbi rd, Landau 85.6 (14) Oldsmobile F-85, Cutlass, Vista Cruiser 86.3 (153) Mercury Montego, Cyclone, Voyager 86.6 (52) Total % nvolvement 89.1 (9,523) % = (1) Accidents Within 15 Miles of Residence for a Given Make/Model Total Accidents for a Given Make/Model

42 Table B.29. Percent Accidents Within 15 Miles of Residence Vehicle Body Type Type ntermediate Sub-compact Compact Sub-Compact/Mi ni Super Sport Standard/Ful 1 Si ze Speci a1 ty/pony Luxury Sedan European Sports Car Personal Luxury % nvolvement (N) 91. (1,416) 9.9 (386) 9.6 (1,158) 9.2 (265) 9. (5) 89.7 (2,337) 89.6 (718) 89.3 (177) 88.6 (132) 86.4 (192) Total % nvolvement % = (1) Accidents Within 15 Miles of Residence for a Given Body Type Total Accidents for a Given Body Type

43 of 98% involvement,in accidents within 15 miles of the residence for the AMC Classic, Rebel, Matador class and a minimum of 8% for the Buick Riviera. When looking at body type classes, however, the maximum involvement is 9.9% for both sub-compacts and inter- mediates; the minimum involvement is 86.4% for personal luxury vehicles; while the involvement frequency for the total sample is 89.1%. Obviously, the differences from the mean are not great. t is, therefore, difficult to establish any correlation between residence proximity and vehicle classes in accident causation. With exposure data, these conclusions may change. Driver Occupation n sorting out the role of vehicle handling in accident causation, a major question that must be answered concerns whether it is the vehicle that causes the accident or the driver who. chooses and drives the vehicle. Driver sex, age, and occupation are three of the factors that have been traditionally examined in attempting to answer this question. Driver occupation is discussed here, with sex and age being discussed in the following sections. Make/model and body type classes for the most and least involved vehicles in accidents with professional people as drivers are given on Tables 8-3 and 8.31, respectively. Such drivers are most involved in accidents with luxury sedans and super sport classes and 1 east involved with special tylpony and sub-compacts. The least involved types are not greatly less than 'the involvement of the total sample, while the most involved types approach almost twice the involvement frequency of the total sample. Similar rankings for clerical and sales people are shown on Tables B.32 and B.33. These people are more apt to be involved in accidents with sub-compact, sub-compact/mini, and super sport classes of vehicles. luxury models. The least involvements are with standard and Note, however, that the involvement of sub-compact vehicles for this class of drivers is over 5% higher than that of the total sample, while the least involved vehicle types are not

44 Table B.3. Percent Accidents with Professional People as Driver. Make/Model % nvolvement (N) Most nvol ved Cadi 11 ac Ca1 ai s, DeVi 1 le, Brougham 15.4 (78) Buick LeSabre, Wildcat, Centurion 12.5 (96) Oldsmobile F-85, Cutlass, Vista Cruiser 12.4 (153) 1 dsmobi 1 e (58) Buick Riviera 12. (5) Chrysl er 11.1 (126) Least nvolved AMC Ambassador Ponti ac Tempest, GTO, Safari Chevy, Nova, Corvai r Camaro VW Beetle Fi rebi rd Mustang, Mach 1, Grande, Boss AMC Classic, Rebel, Matador Total % nvolvement 8. (9,149) % = (1) Accidents with Professional People as Drivers for a Given Make/Model - Total Accidents for a fen ~ake/eodel

45 Table B.31. Percent Accidents With Professional People as Drivers Vehicle Body Type Type % nvolvement (N) Luxury Sedan Super Sport Sub-Compact/Mi ni Personal Luxury European Sports Car ntermediate Compact StandardFull Si ze Sub-compact Speci a1 ty/pony Total % nvolvement % = (1) Accidents With Professional People as Drivers for a Given Body T~E Total Accidents for a Given Body Type

46 Table Percent Accidents With Clerical and Sales Pe'ople as Drivers Vehicle Make/Model Ma ke/model % nvolvement (N) Most nvol ved Pinto 35 (214) Mercury Montego, Cyclone, Voyager 33 (52) Ford Capri 3 (61 Toyota Corona, Crown 28 (97) Vega 26 (153) Fi rebi rd 25 (6) Ope1 Kadette, 19, Rayle 25 (56) Least nvolved VW Beetle 12.4 (41) Dodge Coronet, Charger 13. (123) Dodge Pol ara, Monaco ' 14.6 (82) Plymou th Be1 vedere, Sa tell i te, GTX 15.4 (156) Chrysl er 15.9 (126) Bui c k Ri vi era 16. (-5) Buick Electra (55) Total % nvolvement 2.1 (9,149) (1)Accidents with Clerical and Sales People as Drivers for a Given MakeModel % = - Total Accidents for a Given MakeModel

47 Table Percent Accidents With Clerical and Sales People as Drivers. Vehicle Body Type Type Sub-compact Super Sport Sub-Compact/Mi ni Speci a1 ty/pony European Sports Car Compact Personal Luxury ntermediate Luxury Sedan Standard/Full Size % nvolvement (N) 3.1 (386) 24. (5) 23.4 (265) 22.1 (718) 22. (132) 2.6 (1,158) 2.3 (192) 19.7 (1,416) 19.1 (177) 18. (2,337) Total % nvolvement % = (1)Accidents With Clerical and Sales People as Drivers for a Given Body Type Total Accidents for a Given Body Type

48 appreciably below the total sample frequency. Thus, the pre- ponderance of accidents with sub-compact vehicles is substantially above the other classes of vehicles. (Note also that the number of cases is high, which lends further credence to this finding.) Least and most involved vehicle rankings for skil led and semi-skilled workers are shown on Tables 8.34 and These people experience almost twice the frequency of the total sample of accidents in super sport type vehicles. Experience in other classes of vehicles is not substantially different from the total sample. t is noteworthy that the highest involvement in accidents for a specific make/model (nearly twice the total sample involvement) is with the VW Beetle. Rankings for accidents i nvol vi ng housewives and domesti cs as drivers are shown on Tables B.36 and B.37. t is clearly evident that such drivers are primarily involved in accidents with luxury model vehicles and least involved with the sporty vehicles. There is a suspicion that in two-car families, one car is often a larger luxury model or station wagon which is used for family transportation, while the other is a smaller vehicle used for sing1 e-occupant commuting. With chi 1 dren in school and the husband away at work, the larger vehicle is used by the housewives in mid- day transportation. accident experience. speculations, however. This scenario could account for the indicated Exposure data is necessary to confirm such Vehicles involved least and most in accidents.with students and children as drivers are ranked on Tables B.38 and B.39. There is also clear evidence here that the most involved vehicles are the European sports car and sub-compact/mini types. Luxury and muscle car classes are the least involved. As wi th skil led and semi-ski 1 led workers, the accident involvement frequency for the VW Beetle is almost twice the total sample frequency for student and child drivers.

49 Table B.34: Percent Accidents with Skilled or Semi-Ski 1 led Workers as Drivers. Vehicle Make/Model Ma ke/model % nvolvement (N) Most nvol ved VW Beetle 29.3 (41) Camaro 23.7 (135) 1 dsmobi 1 e (58) Cadillac Calais, Devil le, Brougham 21.8 (78) Ponti ac Tempest, GTO, Safari 2.2 (178) Cougar 19.1 (89) Thunderbi rd, Landau 18.3 (14) Least nvol ved AMC Ambassador 7. (43) Ope1 Kadett, 19, Rayle 1.7 (56) Buick Electra (55) Mustang, Mach 1, Grande, Boss 11. (327) Buick LeSabre, Wildcat, Centurion 11.5 (96) Bui ck Ri vi era 12. (5) Buick Special, Skylark, Sportwagon 12. (133) Total % nvolvement 15. (9,523) / = (1)Accidents With Skilled or Semi-skilled Workers as Drivers for a Given MakeModel Total Accidents for a Given Make/Model

50 Table Percent Accidents With Skilled or Semi -Ski 1 led Workers as Drivers Vehicle Body Type Type Super Sport Luxury Sedan Sub-Compact/Mi ni Personal Luxury Speci a1 ty/pony ntermediate Standard/Full Size Compact European Sports Car Sub-compact % nvolvement (N) 28. (5) 17.5 (177) 17.4 (265) 16.7 (192) 15.3 (718) 15. (1,416) 14.9 (2,337) 14.7 (1,158) 14.4 (132) 14.3 (386) Total % nvolvement 15. (9,523) % = (1OO)Accidents With Skilled or Semi-skilled Workers as Drivers for a Given Body Type Total Accidents for a Given Body Type

51 Table B. 36. Percent Accidents With Housewives and Domestics as Drivers. Vehicle Make/Model Make/Model % nvolvement (N) Most nvol ved Buick Electra 225 Buick Special, Sky1 ark, Sportwagon AMC Ambassador Chrysl er Mercury Monterey, Park1 ane, Marquis Cadi 11 ac Cal ai s, DeVi 11 e, Brougham AMC American, Hornet Least nvolved Ford Capri 1.6 (61) Fi rebird 3.3 (6) Camaro 3.7 (135) VW Beetle 4.9 (41) Plymouth Be1 vedere, Sate1 1 i te, GTX 5.1 (156) Mustang, Mach 1, Grande, Boss 5.2 (327) Ope1 Kadett, 19, Rayle 5.4 (56) Total % nvolvement 7.2 (9,149) % = (1)Accidents With Housewives and Domestics as Drivers for a Given Make/Model Total Accidents for a ~itenmake/~odel

52 Table Percent Accidents With Housewives and Domes t i cs as Drivers. Vehicle Body Type Type Luxury Sedan Personal Luxury Compact StandardFull Size ntermediate Sub-compact Sub-Compact/Mi ni Speci a1 ty/pony Super Sport European Sports Car % nvolven~ent (N) 12.4 (177) 8.9 (192) 8.5 (1,158) 8.4 (2,337) 8. (1,416) 6.5 (386) 4.91 (265) 4.87 (718) 2. (5).8 (132) Total % nvolvement 7. (9,523) % = (1)Accidents With Housewives and Domestics as Drivers for a Given Body Type Total Accidents for a Given Body Type

53 Table B.38. Percent Accidents With Students and Children as Drivers Vehicle Ma ke/model Make/Model % nvolvement (N) Most nvol ved VW Beetle,31.7 (41) Ope1 Kadett, 19, Rayle 3.4 (56) Toyota Corona, Crown 22.7 (97) Fi rebi rd 21.7 (6) Mustang, Mach 1, Grande, Boss 2.8 (327) AMC Classic, Rebel, Matador 2.4 (88) Dodge Coronet, Charger 19.5 (123) Least nvol ved Cadi1 1 ac Calais, DeVille, Brougham 5.1 (78) Buick Riviera 6. (5) Ford Capri 6.6 (61) Thunderbi rd, Landau 6.7 (14) Chrysler 7.1 (126) Dodge Charger, Chal lenger 8.1 (62) 1 dsmobi 1 e (58) Total % nvolvement 16.4 (9,149) % = (1)Accidents With Students' and Children as Drivers for a Given MakeModel Total Accidents for a Given MakeModel

54 Table Percent Accidents With Students and Children as Drivers Vehicle Body Type Type European Sports Car % nvolvement (N) Sub-Compact/Mi ni Speci a1 ty/pony Compact ntermediate Sub-compact Standard/Ful 1 Size Luxury Sedan Super Sport Personal Luxury Total % nvolvement 15.7 (9,523) % = (1)Accidents With Students and Children as Drivers for a Given Body Type Total Accidents for a Given Body Type

55 n sumary, the highest involved vehicle types by occupation are listed as follows: Professional Cl eri cal /Sal es Skilled/Semi-Skilled Workers Luxury Sedan Super Sport Sub-compact Super Sport Super Sport Luxury Sedan Luxury Sedan Personal Luxury StudentsChi ldren European Sports Car Sub-Compact/Mi ni Some caution should be used in interpreting these results in that the accident involvement frequencies may a1 so correlate highly with vehicle selectior~ and usage patterns. Specific conclusions about vehicle hand1 ing factors in accident causation can be most readily obtained when accident and usage experience do - not carrel ate. Driver Sex There has been much written over the years concerning the different accident patterns among males and females in the driving population. Unti 1 a few years ago, the female had definitely been considered to be the safer driver; this conclusion was based on recorded accident frequencies. driver exposure data--albeit limited-* With the recent acquisition of pattern seems to be emerging that suggests fewer differences between the sexes than had been original ly thought [127]. Among younger drivers, the female seems to be slightly superior. however, the male seems to be slightly superior. n middle and older ages, Further, it appears that the differences are minor if comparisons are made between male and female drivers who have similar mileage exposure.

56 Rankings of most involved and least involved vehicle classes with males as drivers are shown on Tables 8.4 and B.41. A1 though it is obvious that certain vehicles experience a high frequency of accidents with male drivers, few clear patterns are apparent, the main exception being the over-involvement of male drivers in the super sport class of vehicles. At the other extreme, male drivers are least involved (or conversely, female drivers are most involved) with sub-compact vehicles. The difference between accident frequencies with the sub-compact (6.7%) and the invol vement frequency for the total sample (64.7%) is not great, however. Driver Age t is well known that the frequency of accidents for young drivers is the highest for any age segment of the driving popula- tion. age brackets. The lowest accident frequencies occur for drivers in middle Accident frequencies are also high for older drivers, but not as high as for younger drivers. With the expanding population, it is generally true that the number of drivers in a given age bracket decreases with increasing age. That is, there are more drivers between ages 2-24 than there are between ages Further, drivers who are killed at a younger age are not part of the driving population in older brackets, and hence there is a trend toward safe drivers in the older age brackets through natural selection. A1 1 these factors, and more, must be weighed in determining the influence of driver age on accident experience. For example, if there are more drivers in the younger age brackets, then the accident frequencies of drivers in these brackets must be weighted accordingly so as not to distort the results. A most important consideration in determining the role of vehicle hand1 ing in accident causation relates to the make-up of the driving population which chooses to use particular vehicles. f European sports cars have the highest accident experience and younger drivers most frequently drive European sports cars, it is not immediately clear whether the sports car or the younger driver is at fault, or perhaps some combination.

57 Table 8.4. Percent Accidents W i th Male Drivers Vehicle MakeModel MakeModel % nvolvement -(N) Most nvolved Dodge Pol ara, Monaco 79 (82) Dodge Charger, Chall enger 77 (62) Oldsmobile (58) Fi rebi rd 73 (6) Ford Capri 72 (61) Cadi llac Calais, DeVille, Brougham 72 (78) Least nvol ved AMC Ambassador Toyota Corona, Crown Mercury Montego, Cyclone, Voyager Buick Riviera VW Beetle AMC Ameri can, Hornet Dodge Dart, Swinger Plymouth Val i ant, Duster Vega Total % nvolvement 64.7 (9,523) % = (1)Accidents with Male ---- Drivers for a Given Make/Model Total Accidents for a Given ~ake/bfodel

58 Table Percent Accidents With Male Drivers Vehicle Body Type Type Super Sport Luxury Sedan ntermediate Special tylpony European Sports Car StandardFull Size Sub-Compact/Mi ni Personal Luxury % nvolvement (N) 82. (5) 7.1 (177) 67.2 (1,416) 66.4 (718) 65.9 (132) 65.7 (2,337) 63.4 (265) 62.5 (192) Sub-compact Compact Total Z nvolvement % = (1)Accidents With Male Drivers for a Given Body Type Total Accidents for a Given Body Type

59 . TableB.42. Mean Driver Age for Vehicle MakeModel Classes - Code Vehicles Mean Drive* AMC Classic, Rebel, Matador 34.9 AMC Ambassador 38.6 AMC American, Hornet AMC Gremlin Chrysl er 43.6 Dodge Coronet, Charger 29.3 Dodge Pol ara, Monaco 37.8 Dodge Charger, Challenger 28. Dodge Dart, Swinger 33.8 Plymouth Belvedere, Sate1 1 i te, GTX 3.3 Plymouth Fury, Suburban 34.7 Valiant, Duster 33.8 Ford Fai rl ane, Tori no, Fa1 con 32.2 Ford Custom, Galaxie, Country Squire 34. Thunderbi rd, Landau 35.1 Mustang, Mach 1, Grande, Boss 26.1 Maverick, Futura 33.2 Pinto 28.4 Mercury Montego, Cyclone, Voyager 34.7 Mercury Monterey, Parklane, Marquis, 37.8 Colony Park Cougar 29.9 Buick Special, Skylark, Sportwagon 36. LeSabre, Wildcat, Centurion 38.9 Electra Riviera 37.7 Cadi 11 ac Calais, Devil le, Brougham 44.3 Chevrolet Chevel le, Nomad, Greenbrier 31. Be1 Ai re, mpala, Brookwood 32.1 Camaro Chevy, Nova, Corvai r Veg a 26.4 Oldsniobile F-85, Cutlass, Vista-Cruiser Pontiac Tempest, GTO, Safari 28.9 Catalina, Ventura, Bonneville, Granville 36.3 Firebird 24.1 Soyota Corona, Crown VW Beet1 e Ford Capri 26. Ope1 Kadett, 19, Ralye 24.6 Austin Mini, Pmerica, 13, Mini Cooper 41. Mean Age 55

60 Table Youngest and Oldest Mean Driver Age Values Vehicle Make/Model Make/Model - Mean Driver Age (N) Youngest Fi rebi rd Camaro Ope1 Kadett, 19, Ralye Ford Capri Mustang, Mach 1, Grande, Boss Vega VW Beetle 1 des t Cadi 11 ac Cal ai s, DeVi 11 e, Brougham Chrysl er Buick Electra 225 Bui ck LeSabre, Wi 1 dcat, Centurion AMC Ambassador Mercury Monterey, Park1 ane, Marquis Dodge Pol ara, Monaco Mean Age

61 Table.44. Mean Driver Age Rankings of Accident nvolved Vehicle Body Types Type Mean Driver Age European Sports Car Special ty/pony Sub-compact Sub-Compact/Mi ni Super Sport ntermediate Compact Standard/Ful 1 Size Personal Luxury Luxury Sedan Mean Age 32.2

62 n summary, then, there is a general pattern of higher frequencies of accidents at younger ages which tapers off to a relatively stable level after age 3. For some classes of vehicles, namely, special ty/pony, super sport, sub-compact, subcompact/mi ni, and European sports cars, there is a re1 ative over- involvement of accidents wi th younger drivers. For others, such as the personal luxury and 1 uxury sedan classes, there is a relative under-involvement. The question which remains to be answered is whether the drivers or the vehicles are the most culpable factor. Answering this question will require a knowledge of the distribution of ages in the driving population in general and for specific vehicle classes in particular. Seat Be1 t Usaae--Driver Seat belt usage in the context of vehicle hand1 ing has examined because of the speculation that belt usage is an indicator of driver attitudes toward safety, and because it has been conjectured that the stabilizing influence of a seat belt may cause a driver to execute more severe maneuvers (e. g., tighter corneri ng) than would ordinarily be the case. The percent usage of seat belts for make/model and body type classes most and least involved in accidents are given on Tables 8.45 and 8-46, respectively. ndications from the body type classifications are that drivers of smaller vehicles are more likely to be wearing seat be1 ts when involved in accidents than are drivers of larger vehicles. An outstanding exception is the VW Beetle where the usage of seat belts by drivers involved in. accidents is less than one-ha1 f the average. The question of whether a seat belt stabilizes a driver during a maneuver is treated more specifically in the next section where seat belt usage and acci dent frequency on curves is examined.