Three times as many fatal accidents happened on parts of the A9 trunk road not dualled as promised by the SNP Government.
Figures showed the difference in accidents over two years on the main road between Inverness and the southern end of the route at Dunblane.
The government promised more than a decade ago to start work on dualling the entire stretch between Inverness and Perth.
But it has been dogged by delays and rising costs while concern grows about whether it will ever be completed.
The safety record will be raised by Scottish Conservative leader Douglas Ross when he speaks at his party’s UK conference on Sunday.
Mr Ross, a Highlands and Islands MSP, is likely to focus criticism on infrastructure problems in the north.
‘First disappointment’
Highlands Tory MSP Edward Mountain said: “First Minister Humza Yousaf promised to the people of the north that fully dualling the A9 was his first priority, and he would sit down with the finance secretary to get the budget to get it done.
“Instead of his first priority, it was his first disappointment.”
The figures, obtained by the Conservatives, cover the period between 2020 and 2022.
Of the 12 fatal accidents, nine were on non-dualled sections and three were on dual carriageway. Seven of the fatal accidents were just last year.
The figures refer to crashes rather than the total number of any fatalities, which is higher.
The research also looked at all personal injuries on the road between Dunblane in the south and Inverness in the north.
They were more evenly spread, but last year 30 were on non-dualled sections compared with 16 on dualled carriageway.
Deaths and delays
More than 300 people have died on the Perth-Inverness stretch since 1979, when people were already demanding road improvements.
In 2007, the SNP first pledged to dual the route. It was supposed to be done by 2025 but that is now impossible.
The price tag was £3 billion in 2011 but will now be far higher.
Meanwhile, a dualling petition from campaigner Laura Hansler has passed 4,200 signatures as it continues to gather support at the Scottish Parliament.
MSPs met the Kincraig campaigner in summer as part of their own inquiry into the project.
Public spending watchdog Audit Scotland reported on Thursday that the A9 dualling campaign was among those affected by cost pressures and further delays.
So far, 11 miles out of 77 have been completed.
Update ‘this autumn’
We revealed earlier this month that work is under way again to find a contractor to dual a six-mile stretch between Tomatin and Moy in the Highlands.
Government agency Transport Scotland said the latest annual budget includes more than £31 million for road safety.
“An additional £5 million package of targeted shorter-term safety measures is to be delivered between Perth and Inverness between now and 2025,” the agency added.
“Work to determine the most suitable procurement options for the remaining sections of the A9 dualling is now well advanced. As we promised in February this year, we expect to update Parliament on a renewed programme this autumn.”
50 years of waiting: How the campaign for A9 dualling has unfolded
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