A spokesperson said police urge drivers and cyclists to be vigilant whenever they take to the state's roads after the incident on the Lyell Highway.

Officers were patrolling on the West Coast when the "near collision" between the car and two bicycle riders occurred.

Inspector Adam Spencer said the car cut a corner on the 99 Bends, which is the windy section of the Lyell Highway that traverses the mountainous gap between Queenstown and Gormanston, and nearly hit the cyclists.

"Thankfully, the cyclists were OK, however it could have been a very different situation," he said.

"One wrong decision on the road can have tragic consequence and particularly in small, isolated areas, the whole community feels that loss.

"I have delivered those messages to family and friends, and they are heartbreaking."

Inspector Spencer urged drivers to be mindful of cyclists, and to keep a safe passing distance of 1.5 metres when in a speed zone above 60 kmh, and at least one metre when in speed zones of 60 kmh and below.

"Cyclists have an equal responsibility on our roads," he said.

"It was pleasing to see the cyclists involved wearing securely fastened helmets, high-visibility garments and that their bikes were in good condition with working brakes and lights.

Anyone who witnesses dangerous driving can contact police on 131 444 or report anonymously to Crime Stoppers on 1800 333 000.