A rail group has demanded the scrapping of the A9 dualling project – and called for massive investment in the Highland Main Line instead.

Transport Scotland has suggested that the introduction of average-speed cameras has significantly reduced the dangers to motorists on the notorious road.

There were no fatal accidents on the A9 in July, August and September this year – a first since 1992 – while the number of people killed or injured on the route between Dunblane and Inverness fell by 48%.

However, the number of fatal accidents between Perth and Inverness rose by 33.3% in the first nine months after the cameras were installed.

The Rail Freight Group said the figures from Transport Scotland were “great news” – but made the case for doubling the width of the highway redundant, given the average-speed cameras already appeared to be making the road safer.

The body has suggested the £3billion earmarked for dualling the A9 would be better spent on improving the rail network.

A spokesman for the Rail Freight Group said: “The Transport Scotland figures are great news – and must blow a major hole in the case for full dualling of the A9.

“The priority should now be to fund upgrading of the parallel Highland Main Line railway, which is still single track over two-thirds of its length.

“With more and longer crossing loops, or ideally double track throughout, freight trains such as those serving Tesco could be increased in length from 20 to 28 containers – a massive increase in productivity.”

A Transport Scotland spokesman said: “The Scottish Government’s Strategic Transport Projects Review, published in December 2008, formed a multi-modal appraisal of the Perth to Inverness corridor and concluded that both road and rail interventions should be brought forward.

“Progressing both improvements will improve road and rail transport for passengers and freight in the Perth to Inverness corridor.

“Transport Scotland officials are working closely together to ensure that the optimum solution is found for both projects. This will ensure that the projects both meet the objectives and, as a consequence, provide value for money.”