Saving Lives Together

Physics of Speed

Fatalities on WA roads so far for 2019

You decide your speed.
Physics decides the rest.

Launch game

Stopping distance quick facts

Select a speed below to see how the chances of a pedestrian surviving a crash reduces with an increasing impact speed.



How long it takes to stop?

Select a speed below to see how it affects the time to react and stop whether you're driving a car or truck or riding a motorcycle.




Dry 9m

Wet 13m

Total distance to stop: 26m — 30m




Dry 13m

Wet 18m

Total distance to stop: 26m — 30m




Dry 9m

Wet 18m

Total distance to stop: 20m — 29m

Tunnel vision effect

See how speed affects your peripheral vision.

Photo of a country road Photo of a country road - blurred

Factors affecting stopping distance

  • Attention icon


    Good concentration allows drivers to notice hazards and make decisions about the best way to react.

  • Fatigue icon


    Fatigue slows reaction time and reflexes. Get 7.5 hours sleep before a long drive.

  • Vision Impairment icon

    Alcohol and Drugs

    Alcohol slows reaction times, while drugs can lead drivers to overestimate their abilities.

  • Age & Experience icon

    Age and Experience

    Young people have sharper senses but older people have more experience.

  • Vehicle Age icon

    Vehicle Age

    Older vehicles may not have five-star safety ratings, check ANCAP.

  • Type & Conditions of Tyres icon

    Type and Condition of Tyres

    It’s important to check your vehicle’s tyre pressure.

  • Safety Features of Vehicle icon

    Safety Features of Vehicle

    Look for Anti-lock braking Systems and Auto Emergency Braking.

  • Vehicle Weight icon

    Vehicle Weight

    Ensure loads are positioned near the front of the vehicle and allow longer slowing time.

  • Road Surface icon

    Road Surface

    Gravel shoulders can cause vehicles to skid off the road.

  • Road Gradient icon

    Road Gradient

    Be aware that it’s easy to pick up speed down hills.

  • Road Alignment icon

    Road Alignment

    Even slight curves can cause vehicles to leave the road.

  • Weather Conditions icon

    Weather Conditions

    Slow down in slippery conditions as braking distance is longer.

Acknowledgement of Country

The Government of Western Australia acknowledges the traditional custodians throughout Western Australia and their continuing connection to the land, waters and community.
We pay our respects to all members of the Aboriginal communities and their cultures; and to Elders both past and present.

The Road Safety Commission is a portfolio within WA Police Force. It reports to the Minister for Road Safety, Hon. Michelle Roberts MLA.