Average speed cameras have been brought in to tackle the A9's appalling accident record.
Nearly 300 motorists have been caught since controversial average-speed cameras were installed along the A9 three months ago.
Official numbers released by the A9 Safety Group shows that overall speeding is down from around one in three to one in 20.
The stats, which were released to show the effectiveness of the Inverness-Dunblane system, note that excessive speeding, involving motorists travelling at more than 10mph above the limit, is down by 97%.
As predicted, journey times along the stretch have increased.
Transport Scotland’s Stewart Leggat, who chairs the safety group, said the stats are “very encouraging”.
He said: “All the early findings on speed, journey times and journey time reliability are in line with our predictions, while traffic volumes on the A9 are remaining higher than in 2013, with no evidence of drivers diverting onto other routes.”
The cameras, nicknamed “yellow vultures” were introduced at 27 locations on sections of single-carriageway between Perth and Inverness.
