Vehicle Crashworthiness Ratings and Crashworthiness by Year of Vehicle Manufacture : Victoria and NSW Crashes During 1987-96

Monash University Accident Research Centre - Report No. 128 - 1998

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

Full report in .pdf format [2.3MB]

Abstract:

Crashworthiness is the relative safety of vehicles in preventing severe injury in crashes. Crashworthiness ratings for 1982-96 model vehicles were developed based on data on crashes in Victoria and New South Wales during 1987-96. 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 85,585 drivers injured in crashes in the two States. Injury risk was based on 431,690 drivers involved in crashes in New South Wales where a vehicle was towed away. The ratings were adjusted for the driver sex and age, the speed limit at the crash location, and the number of vehicles involved, factors which were found to be strongly related to injury risk and/or severity. They 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 44 models of passenger cars, four-wheel drive vehicles, passenger vans and light commercial vehicles which 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 1996. The data covered 1,077,352 drivers involved in tow-away crashes in New South Wales during 1987-96, and 263,000 drivers injured in crashes in Victoria or New South Wales during the same period. Cars, station wagons and taxis manufactured during the years 1964 to 1996 were considered.

The results of this report are based on a number of assumptions and warrant a number of qualifications which 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 1982-96 model vehicles based on crash data from Victoria and New South Wales. 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 85,585 drivers injured in crashes in the two States during 1987-96. Injury risk was based on 431,690 drivers involved in crashes in New South Wales where a vehicle was towed away.

The crashworthiness ratings were adjusted for the driver sex and age, the speed limit at the crash location, and the number of vehicles involved, factors which were found to be strongly related to injury risk and/or severity. These adjustments were made with the aim of measuring the effects of vehicle factors alone, uncontaminated by other factors available in the data which 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 44 models of passenger cars, four-wheel drive vehicles, passenger vans and light commercial vehicles which 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 which 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 1996. This study updated an earlier one which studied vehicles manufactured in the years 1964 to 1995.

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 1996. 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 1996.

This project was funded as contract research by the following organisations: Road Traffic Authority of NSW, Royal Automobile Club of Victoria Ltd., NRMA Ltd., Federal Office of Road Safety and VicRoads