Novice drivers' crash risk before and after the age limit for driver training in Norway was lowered from 17 to 16 years.

Self-report data on crashes and exposure were collected from 10 300 drivers, who had held a license between 2 and 18 months and had passed the driving test between April, 1998 and March, 1999. These drivers could legally drive with a private instructor from the age of 16, since the age limit was lowered from 17 years in 1994 (the licensing age was kept at 18). These drivers' post-licensing risk did not differ significantly from that of drivers who got their license before or immediately after the age limit was lowered. The lowered limit had only a small effect on the amount of training. A recent tendency to increased involvement of 18-year-old drivers in police-reported injury crashes is probably explainable by regional differences regarding changes in exposure and a decrease in licensing among young people. On this background, the amount of prelicense driving must probably be increased considerably to have measurable effects on post-licensing crash risk.