Queenstown police are urging motorists, particularly skiers, to check their vehicle's tyres and drive to the conditions.
As skifields around the Queenstown Lakes District prepare to open for the season, police this week launched a winter driving operation.
Road policing Sergeant Kate Pirovano said she ran a checkpoint on the opening day of the Remarkables ski area, and was concerned at the state of tyres on vehicles.
"Ice and grit can catch you out even with good tyres, so there's a higher element of risk,'' she said.
"A lot of crashes you attend, one of the first things you do is take a photo of the tyres. They generally can be a factor.''
Fatigue could also be an issue, as people heading to the skifields often drove long distances without breaks.
There would be more checkpoints as part of the operation, including this weekend during Queenstown's Winter Festival, she said.
"The priority for us is to remain highly visible.''
Police would also be handing out window scrapers and cloths, to remind drivers to clear their windows of ice before venturing out on the road.
"No peepholes on the front windscreen - it's very dangerous,'' Sgt Pirovano said.
Passenger transport operators taking people up and down the mountains were also being asked to do proactive safety checks on their vehicles.
