The A9 is shut in both directions at Drumochter after a car collided with a BEAR Scotland gritter that was helping an HGV in snowy conditions.
Emergency services were called to the scene between Wade Bridge and Dalnacardoch Lodge at about 2.10pm. It is understood no-one was seriously injured in the crash.
Two minor one-vehicle accidents happened nearby at Dalwhinnie, police said.
Motorists travelling to and from the Highlands have been warned to expect long delays as a result of the closure.
Snow and blizzard conditions are badly affecting other parts of the A9 and police have advised drivers to take extra care.
The Met Office earlier issued yellow "be aware" warnings of snow and ice for much of the country today and into tomorrow.
Accumulations of 2cm to 5cm were expected on ground above 200 metres, with up to 10cm falling on higher routes above 300 metres, forecasters said.
Gale-force winds are also forecast to hit Shetland overnight with gusts of up to 80mph expected.