What makes up total stopping distance

Empty trucks require greater stopping distance. An empty vehicle has less traction. The brakes are designed to control the maximum weight of the unit; therefore, the brakes lock up more readily when the trailer is empty or lightly loaded. This can cause skidding and loss of control. Slippery when wet Shady parts of a road will remain icy and slippery long after open areas have melted. Bridges freeze before the road freezes.

Be careful when the temperature is around 32 degrees F. Slight melting makes ice wet. Wet ice is more slippery than ice that is not wet. Black ice is a thin layer that is clear enough that you can see the road underneath. It makes the road look wet. When the temperature is below freezing and the road looks wet, watch for black ice. If ice is on the front of your mirror, mirror support or antenna, the road surface is probably starting to ice up.

Roads are very slippery when rain first begins. Just after rain begins, water mixes with oil on the road making it unusually slippery. Take your foot off the accelerator. This will slow your vehicle and let the wheels turn freely. Do not use the brakes to slow down. If the drive wheels begin to skid, steer in the direction you want to go. Speed and Curves If you take a curve too fast, your tires can lose traction with the road. Slow to a safe speed before you enter a curve.

Braking in a curve is dangerous because you can lock the wheels and cause a skid. Never exceed the posted speed limit for a curve. Speed and Distance Ahead You should always be able to stop within the distance you can see ahead. Fog, rain or other conditions may require you to slow down.

At night, you can't see as far with low beams as you can with high beams. When you use low beams, slow down.

At 60 mph you travel roughly 18m during the time it takes you to react. Braking distance is the distance that it takes your vehicle to come to a full stop starting from when you start applying the brake. At 60 mph you need roughly 55m to come to a stop in good conditions. Speed makes a very big difference to your ability to stop in time and a significant difference to your chance of being involved in a crash.

Doubling the speed will increase thinking distance by 2 and braking distance by 4. Failure to leave enough space in front is called tailgating. Tailgating leads to limited vision and less time to respond in case the vehicle in front needs to brake and is a common cause of rear-end crashes.

That way you can avoid having to brake hard if the car in front brakes suddenly. Many drivers, drive in a false belief that if the car in front suddenly started braking, they would react and brake and end up stopped the same distance apart. The total stopping distance of a vehicle is made up of 4 components. The human perception time; is how long the driver takes to see the hazard, and the brain realize it is a hazard requiring an immediate reaction.

Once the brain realizes danger, the human reaction time is how long the body takes to move the foot from accelerator to brake pedal. These first 2 components of stopping distance are human factors and as such can be effected by tiredness, alcohol, fatigue and concentration levels. A perception and reaction time of 3 or 4 seconds is possible. Once the brake pedal is applied there is the vehicles reaction time which depends on the brake pedal free-play, hydraulic properties of the brake fluid and working order of the braking system.

This is why the tailgating car usually cannot stop, when the brake light came on in the car in front, this driver had already completed the perception, human and vehicle reaction periods. The following driver was perhaps 1 second to late in applying the brakes.