Vehicle Crashworthiness Ratings and Crashworthiness by Year of VehicleManufacture: Victoria and NSW Crashes During 1987-97, Queensland Crashes During 1991-96

Monash University Accident Research Centre - Report #150 - 1999

Full report in .pdf format [8.7MB]

Authors: Newstead, S.V., Cameron, M.H. & Le, C.M.

Abstract:

Crashworthiness is the relative safety of vehicles in preventing severe injury in crashes. Crashworthiness ratings for 1982-97 model vehicles were developed based on data on crashes in Victoria and New South Wales during 1987-97 and in Queensland during 1991-96. Crashworthiness was measured by a combination of injury severity (of injured drivers) and injury risk (of drivers involved in crashes). Injury severity was based on 113,531 drivers injured in crashes in the three States. Injury risk was based on 518,726 drivers involved in crashes in New South Wales and Queensland where a vehicle was towed away. The ratings were adjusted for the driver sex and age, the speed limit at the crash location, the number of vehicles involved, the state in which the crash occurred and the year in which the crash occurred. These factors were found to be strongly related to injury risk and/or severity. The ratings estimate the risk of a driver being killed or admitted to hospital when involved in a tow-away crash, to a degree of accuracy represented by the confidence limits of the rating in each case. The estimates and their associated confidence limits were sufficiently sensitive that they were able to identify 55 models of passenger cars, four-wheel drive vehicles, passenger vans and light commercial vehicles that have superior or inferior crashworthiness characteristics compared with the average vehicle.

Also investigated is the relationship between vehicle crashworthiness and the year of manufacture of Australian vehicles manufactured from 1964 to 1997. The data covered 1,292,150 drivers involved in tow-away crashes in New South Wales during 1987-97 and Queensland during 1991-96, and 309,729 drivers injured in crashes in Victoria, New South Wales or Queensland during the same periods. Cars, station wagons and taxis manufactured during the years 1964 to 1997 were considered.

The results of this report are based on a number of assumptions and warrant a number of qualifications that should be noted.

Executive Summary

This report describes the development of further updated crashworthiness ratings (the relative safety of vehicles in preventing severe injury in crashes) for 1982-97 model vehicles based on crash data from Victoria and New South Wales during 1987-97 and from Queensland during 1991-96. Crashworthiness was measured by a combination of injury severity (of injured drivers) and injury risk (of drivers involved in crashes). Injury severity was based on 113,531 drivers injured in crashes in the three States during 1987-97. Injury risk was based on 518,726 drivers involved in crashes in New South Wales and Queensland where a vehicle was towed away.

The crashworthiness ratings were adjusted for the driver sex and age, the speed limit at the crash location, the number of vehicles involved, the year in which the crash occurred and the state in which the crash occurred. These factors were found to be strongly related to injury risk and/or severity. Adjustments were made with the aim of measuring the effects of vehicle factors alone, uncontaminated by other factors available in the data that affected crash severity and injury susceptibility.

The rating scores estimate the risk of a driver being killed or admitted to hospital when involved in a tow-away crash, to a degree of accuracy represented by the confidence limits of the rating in each case. The estimates and their associated confidence limits were sufficiently sensitive that they were able to identify 55 models of passenger cars, four-wheel drive vehicles, passenger vans and light commercial vehicles that have superior or inferior crashworthiness characteristics compared with the average vehicle.

It is concluded that the additional crash data has enabled the crashworthiness ratings to be obtained for a larger range of car models than previously. The new data set has been able to produce more up-to-date and reliable estimates of the crashworthiness of individual car models than those published previously. However the results and conclusions are based on a number of assumptions and warrant a number of qualifications that should be noted.

A second stage of the project investigated the relationship between vehicle crashworthiness and the year of manufacture of vehicles for the years of manufacture 1964 to 1997. This study updated an earlier one that studied vehicles manufactured in the years 1964 to 1996.

The crashworthiness of passenger vehicles (cars, station wagons and taxis), measured by the risk of the driver being killed or admitted to hospital as the result of involvement in a tow-away crash, has been estimated for the years of manufacture from 1964 to 1997. This study showed similar patterns of improvements in crashworthiness over the period of study to the original study with the greatest gains over the years 1970 to 1979 during which a number of new Australian Design Rules aimed at occupant protection took effect. Gains in crashworthiness have also been observed over the years 1989 to 1997.

Sponsoring Organisations: Road Traffic Authority of NSW, Royal Automobile Club of Victoria Ltd., NRMA Ltd., VicRoads and by a grant from the Federal Office of Road Safety