A9 average speed cameras 'changing driver behaviour'
Average speed cameras have resulted in a "significant shift in driver behaviour" on the A9, according to safety campaigners.
New figures from Police Scotland show the number of vehicles speeding on the road has dropped from one in three to one in 15 since the cameras were introduced in October.
However, the number of speeders caught in the last quarter rose compared to the first three months of the system.
Bosses said this was "not unexpected".
The average speed camera system was controversial before it was installed, with critics claiming it would have little impact on safety and increase journey times, while disrupting traffic flow on the road.
The A9 was long considered one of the country's most dangerous roads, with the Scottish government committing £3bn to convert the full length of the Perth to Inverness route to dual carriageway.
In total, 1,744 vehicles were detected speeding in the A9 enforcement area between 28 October and 20 April, which the group said indicated an "extremely high level of compliance".
This works out as an average of ten cars caught speeding per day, from an average volume of 10,000 vehicles travelling between Inverness and Perth and 24,000 between Dunblane and Perth.
The figures also displayed a downward trend in the number of crashes on the road.
About driver in every 20 was caught travelling at excess speed in the three months after the cameras were introduced in October.
That number rose in subsequent months to one in 15, but Stewart Leggett, chairman of the A9 Safety Group - a body which involves Transport Scotland, police and road maintenance companies - said the rise was "not unexpected".
He said: "The latest data shows that in the areas covered by cameras compliance rates remain exceptionally high.
"The monitoring equipment on the route clearly indicates that there has been a significant shift in driver behaviour with the number of vehicles exceeding the speed limit reduced from one in three to one in 15.
"And more importantly the number of vehicles travelling at 10mph above the limit has been maintained at a level of around 1 in 250 since the cameras were introduced."