Do age-based mandatory assessments reduce older drivers' risk to other road users?

To assess whether different licensing policies were associated with different fatality levels, the fatality outcomes of older drivers in Victoria and New South Wales (NSW) were compared. In Victoria, there is no age-based assessment required for re-licensing, while in NSW, drivers aged 80 years and older are required to provide annual medical certificates and from age 85, are required to pass on-road driving tests. Fatality rates associated with older drivers in each jurisdiction were calculated for the main categories of road users on two bases: per number of target drivers and per number of licensed drivers. When fatality outcomes were considered relative to the number of 80-plus year-olds in the Victorian and NSW populations, there was no significant difference in the overall fatality rate between the two groups. Similarly, there was no significant difference between the two groups in terms of the fatality rate for all other road users and for road users not in the older drivers' vehicles. When fatality outcomes were considered relative to the number of 80-plus year-old licensed drivers in either Victoria or NSW, Victorian older drivers were associated with a lower overall fatality rate and the difference was marginally statistically significant. Victorian older drivers were also associated significantly lower fatality rate for road users not in the older drivers' vehicles. Victorian older drivers represented a statistically significant higher risk in one major regard: to their passengers. Victorian drivers aged 80 years and older had between two and three times higher passenger fatality rates compared to NSW drivers. However it was also found that Victorian older drivers had a significantly higher passenger occupancy rate than their NSW equivalents. Once Victorian and NSW older drivers' different passenger occupancy rates were controlled for, there were no statistically significant differences across the two jurisdictions. These findings collectively suggested that age-based mandatory assessment programs do not have demonstrable safety benefits, in terms of either total fatalities or other road user fatalities--thereby broadly confirming the findings from previous research based on older driver crash involvement.