Transport for NSW is urging motorists in the Snowy Mountains to drive to the conditions and to carry chains for all two-wheel drive vehicles following an increase in road incidents on alpine roads during the school holidays.

The July school holidays brought its usual influx of visitors to the region and with it, more motor vehicle accidents. Transport for NSW executive director, Rob Austin, said an increase in road incidents has prompted an important reminder for motorists to slow when conditions worsen and to be prepared to fit chains.

"In the first week of the school holidays, we saw a large increase in road incidents on Alpine roads," Mr Austin said.

"More than 60 per cent of incidents during this first week were due to ice on the road and motorists not using chains on their vehicles.

"We also saw an increase in motorists entering Kosciuszko National Park, which resulted in the implementation of the Kosciuszko Road Traffic Management Plan. More than 200 cars were turned around due to the car park in the national park reaching capacity."

All two-wheel vehicles entering the national park between the June and October long weekends must carry snow chains and fit them as directed by traffic control or signage.

Transport for NSW is also encouraging four-wheel drive motorists to consider using snow chains.

"Please slow down when conditions get worse and drive with caution in fog, snow or on ice," Mr Austin said.

Travellers can leave the car at their accommodation or home, and make use of the Snowy Mountains Bus Service connecting Cooma, Berridale and Jindabyne with Perisher, and Thredbo and the skitube at Bullocks Flat.

The service lets skiers, snowboarders and day-trippers skip alpine driving. Tickets also include entry to Kosciuszko National Park.

The Snowy Mountains Bus Service runs seven days a week until Sunday 4 October.