Trrl Lr 931
In order to compare advanced driving tests run by the Institute of Advanced Motorists (IAM) with Department of Transport (DTp) learner driver tests, TRRL Driving Consultants who had been DTp driving examiners, observed 120 IAM tests and assessed and marked faults according to DTp procedure. Although differences were found between the marking procedures in the two forms of tests, in 103 cases out of 120 there was agreement on pass/fail decisions. The total number of serious and dangerous faults recorded by the TRRL Driving Consultants increased as thest proceeded when the number of faults in each separate successive 30 minute period out of the 90 minute test was examined. The 'pass' rates, based on the proportion of candidates who did not show such faults, decreased with the duration of the driving test from 83 percent after 30 minutes to 52 per cent after 90 minutes