New slip roads for a 70-mile stretch of the A9 will cause drivers to lose control and skid on to oncoming traffic, it is feared.
Transport Scotland bosses have selected a preferred design for junctions on the trunk road when it is dualled, which Highland councillor Andrew Jarvie has said will cause accidents as the corners are too sharp.
From Killiecrankie near Pitlochy to Moy, south of Inverness, the "half cloverleaf" design has been suggested for many of the slip roads which Councillor Jarvie, who represents Inverness South, is insisting is unsuitable for such a rural area which, is 200 metres above sea level and regularly sees heavy snowfall throughout the winter.
He has said sharper turns will be required and in snow or ice cars will veer off the road and skid into oncoming traffic on the A9 - the main link between the Highlands and the central belt.
"For most of the time it will be fine but when we have bad weather slip roads are often the last to be cleared," the Conservative councillor said.
"Often by the time the road is cleared most of the day has gone by before the slips roads are done and they certainly won’t be done overnight.
"The shape of these slip roads will basically mean travelling for about 20 metres going at a 90 degree angle which is totally unsuitable for an area like this, given the weather conditions.
"When it snows it can take a plougher an hour and a half to get there in bad weather and even then the main road has to be done before they can go back and do the slip roads.
"It defies belief."
The Granish turn off will be a half cloverleaf junction with underbridge so traffic will go beneath the main carriageway to join the A9.
The same design is proposed for Blackmount – the turn off for Carrbridge and onwards to Moray for traffic heading from the Inverness direction.
However, an overbridge is proposed at Aviemore south and a so-called ghost island will be used for traffic turning onto the B9152 Aviemore-Kincraig road.
Councillor Jarvie said he has raised the half clover issue at recent public constulations for the £3 billion project, which will see the A9 completely dualled between Perth and Inverness by 2025 but said the concerns have fallen on deaf ears.
Now he has written to those behind the project to highlight the risks of the cloverleaf design as opposed to the wider "diamond" design which was initially considered.
He said: "I am concerned that this design means that motorists will have to turn 90 degrees in a very short distance which will inevitably lead to cars losing control.
"Even more concerning in this design is that on the outside of the corner, where motorists will skid off the road, is the oncoming carriageway for cars joining the A9.
"The safest option at these higher elevations would be the diamond design which not only has the longest distance to allow motorists to slow down, but also means that there is no oncoming traffic on the same slip lane."
A Transport Scotland spokesman defended the choice of junction, saying: "The compact grade-separated junction layouts which the public got an opportunity to see and comment on at the recent drop-ins have been developed in line with national design standards and following comments received after the preferred option exhibitions earlier this year.
"These junctions have a significantly reduced footprint with reduced environmental and visual impacts.
"They also improve connections to side roads, non-motorised user routes and private accesses and provide for the safe use and operation of the trunk road and its junctions. We have received considerable positive feedback on these proposals."
But this did not convince Cllr Jarvie, who said a national design which is suitable elsewhere will not work in the north.
"A ‘national design standard’ may well be fine for the rest of the country but is entirely unsuitable for the stretch between Killiecrankie and Moy," he said.