The shocking death toll on the A9, the main road link between central Scotland and the Highlands, has prompted campaigns for improved safety measures and better driving standards for many years.

According to the latest available official statistics, there were 67 deaths and more than 1200 collisions between 2006 and 2010, The fatal collision earlier this month in which a mother and her seven-year-old daughter and a German tourist were killed has renewed the focus on how to reduce the danger on what has been dubbed Scotland's "killer road".

Repeated switching between dual and single carriageway driving is a problem, with a disproportionate number of accidents occurring on the two-way stretches, where long queues build up behind slow-moving vehicles, leading to frustration and risky overtaking. Despite £50 million being spent on safety measures in the past six years, there are accidents at notorious blackspots on the single stretches and around some junctions.

The Scottish Government is committed to dualling the remaining 80 miles of single carriageway but the £3 billion project is only at the stage of inviting bids. Work is not scheduled to begin until 2015 and will not be completed until 2025, raising the prospect of scores more fatalities before that time.

The announcement that average speed cameras are to be installed next year and will be operational between Dunblane and Inverness by next summer is a welcome and timely move towards improving safety in the shorter term. It is also a recognition that while the engineering solution of dualling will provide the best outcome, driver behaviour is a key factor in the safety of every road. A police crackdown on speeding on the A9 last year resulted in 687 motorists charged for speeding between Perth and Inverness over a 10-day period.

Speed is not the cause of every accident but it is a significant element in many (and there have been instances of drivers travelling at more than 100mph on the A9). Average speed cameras have been shown to be effective in reducing carnage on the A77 in Ayrshire. In the seven years since they have been in operation on that route, fatal accidents have been reduced by 46% and serious ones by 35%.

The cost of installing them over the 140 miles of the A9 between Dunblane and Inverness is considerable at £2.5m. It is inevitable this will trigger debate about whether that sum could be more effectively used and there will be concerns about the technicalities of different speeds on different carriageways and for different classes of vehicle.

It is not a question of putting all the eggs in one basket. The A9 Safety Group is to look at ways of improving signage and road barriers. Chief Superintendent David O'Connor, president of the Scottish Police Superintendents' Association, who was prompted by the latest fatal accident to call for the timetable for dualling the entire route between Perth and Inverness to be brought forward, welcomed the introduction of average-speed cameras as likely to focus drivers' attention on speed.

That will help but cameras should not entirely replace visible police patrols which raise driving standards, including safe overtaking and using lay-bys to allow others to pass. All are necessary to reduce accidents.