Vehicle safety ratings estimated from police reported crash data: 2005 update. Australian and New Zealand crashes during 1987-2003

Monash University Accident Research Centre - Report #241 [2005]

Authors: S. Newstead, M. Cameron & L. Watson

Full report in .pdf format [1.6MB]

Abstract:

Crashworthiness ratings measure the relative safety of vehicles in preventing severe injury to their own drivers in crashes
whilst aggressivity ratings measure the serious injury risk vehicles pose to other road users with which they collide.
Updated crashworthiness ratings and aggressivity ratings for 1982-2003 model vehicles were estimated based on data on crashes in Victoria and New South Wales during 1987-2003 and in Queensland, Western Australia and New Zealand during 1991-2003. Both crashworthiness and aggressivity were measured by a combination of injury severity (the risk of death or serious injury given an injury was sustained) and injury risk (the risk of injury given crash involvement). The ratings were adjusted for the sex and age of the person whose injury outcome was being measured, speed limit at the crash location, number of vehicles involved where relevant, the jurisdiction in which the crash occurred and the year in which the crash occurred. These factors were strongly related to injury risk and/or severity. The ratings estimate the risk of being killed or admitted to hospital when involved in a crash, to a degree of accuracy represented by the confidence limits of the rating in each case.

Crashworthiness estimates and their associated confidence limits were obtained for 288 vehicle models classified into 12
market groups. They were sufficiently sensitive that they were able to identify 149 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. A new aggressivity rating was successfully developed which extended the previous
rating to consider the injury outcomes of not only drivers of other vehicles but also of unprotected road users such as
pedestrians, cyclists and motorcyclists. The new aggressivity rating measured the risk of death or serious injury to other
drivers or unprotected road users impacted by the focus vehicle. In addition to the above factors this rating was also
adjusted for type of other road user impacted as this factor was strongly related to injury severity and varied between
vehicle models. New aggressivity rating estimates and their associated confidence limits were obtained for 261 vehicle
models and were sufficiently sensitive that they were able to identify 115 models of passenger cars, four wheel drive
vehicles, passenger vans and light commercial vehicles that have superior or inferior aggressivity characteristics compared with the average vehicle.

Also investigated was the relationship between vehicle crashworthiness and the year of manufacture of Australian
passenger and light commercial vehicles manufactured from 1964 to 2003. Trends were examined by year of manufacture both for the fleet as a whole and by market group for vehicles manufactured from 1982 to 2003.

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

Sponsoring Organisations - This project was funded as contract research by the following organisations:
Road Traffic Authority of NSW, Royal Automobile Club of Victoria Ltd, NRMA Ltd, VicRoads, Royal Automobile Club of Western Australia Ltd, Transport Accident Commission and Land Transport New Zealand, the Road Safety Council of Western Australia, the New Zealand Automobile Association and by a grant from the Australian Transport Safety Bureau