Ice and snow change how a car grips the road, steers, and stops. Winter driving safety matters because a small mistake at normal speed can become a long slide on a low-friction surface. Students who understand traction, stopping distance, and visibility can make safer choices before and during travel.
The safest winter trip starts with slowing down, increasing following distance, and preparing for emergencies.
Key Facts
- Friction provides traction between tires and road, and ice greatly reduces this friction.
- Stopping distance increases as speed increases: doubling speed can make stopping distance about four times longer.
- Use the 6 second following rule or more on snow and ice instead of the normal 3 second rule.
- If you skid, look and steer where you want the front of the car to go, and avoid sudden braking.
- Bridge decks, shaded roads, intersections, and ramps freeze first because they lose heat quickly or get polished by traffic.
- Safe winter kit items include a scraper, shovel, blanket, flashlight, phone charger, jumper cables, reflective triangles, water, and snacks.
Vocabulary
- Traction
- Traction is the grip between a tire and the road that allows a vehicle to start, turn, and stop.
- Black ice
- Black ice is a thin, hard-to-see layer of ice that makes pavement look wet or slightly shiny.
- Stopping distance
- Stopping distance is the total distance a vehicle travels from the moment the driver reacts until the vehicle fully stops.
- Following distance
- Following distance is the time or space kept between your vehicle and the vehicle ahead.
- Skid
- A skid is a loss of tire grip that causes a vehicle to slide instead of following the driver's steering or braking input.
Common Mistakes to Avoid
- Driving at the posted speed limit during icy conditions, because the speed limit is for good conditions and may be unsafe when traction is reduced.
- Following too closely behind another vehicle, because stopping distance is much longer on snow and ice and sudden braking can cause a rear-end crash.
- Slamming on the brakes during a skid, because abrupt braking can lock tires or overwhelm traction and make the slide worse.
- Assuming four-wheel drive makes stopping safer, because four-wheel drive can help acceleration but does not shorten braking distance on ice.
Practice Questions
- 1 A car traveling on dry pavement needs 40 m to stop from a certain speed. On packed snow, the stopping distance is about 3 times as long. What is the stopping distance on packed snow?
- 2 You are driving 18 m/s on an icy road and use a 6 second following rule. What minimum following distance in meters should you leave between your car and the car ahead?
- 3 A student sees a shiny patch on a shaded bridge on a cold morning. Explain why this area is especially risky and describe two safe actions the driver should take before reaching it.