Assessing older driver's fitness to drive allowing for a low mileage bias: Using the GRIMPS screening test
Data from 244 older drivers in New Zealand have been used to demonstrate that older drivers who travel low mileages are liable to have more crashes per distance driven than older drivers who travel higher mileages. The results showed that drivers travelling 50 km or less per week had a considerably higher per-distance crash rate than drivers travelling 100 km or more per week. Low mileage drivers also performed significantly worse on both a screening test of fitness to drive (the GRIMPS screening test) and on the New Zealand Older Driver Relicensing Test (NZODORT). With reduced driving performance likely to be a major factor in explaining the association between extent of driving and crash involvement, the findings presented in this paper are valuable in identifying a small, more precisely defined target group for road safety countermeasures, while excluding most older drivers from any special safety scrutiny.