What is the stopping distance of a car and what does it depend on

Maximum concentration and composure is required of the driver driving the vehicle. Since the vehicle is an object of increased danger, then the requirements are appropriate here. It is especially important to regularly check the functionality of the braking system. How quickly the car can stop if a pedestrian appears on the carriageway or another obstacle appears on its serviceability. In this case, we are talking about such a concept as the length of the braking distance.

What is the braking distance of a car

The braking distance is the distance covered by the vehicle from the moment the brake pedal is pressed until it stops completely. It is important to note that the moment when the vehicle's braking system is activated is considered to be the beginning of the braking distance. In the event of an emergency stop, this is indicated by dark tire marks on the asphalt, making it easy to measure this distance. Typically, its length ranges from 5 to 100 meters, depending on a number of factors.

The vehicle cannot stop instantly, since the laws of physics do not allow it to do so. The length of the braking distance is primarily influenced by the speed with which the driver was driving at the moment the brake pedal is pressed. Of course, the faster the car moved, the greater the distance it will have time to travel to a complete stop.

Weather conditions are another important factor affecting stopping distance. For example, ice in general can cause the car to drift into uncontrolled skid. It is very important in winter to use rubber with spikes or Velcro, as well as to observe the speed limit on the highway and in the city. In addition, the grip of the wheels with the road on wet asphalt worsens, which can also lead to an increase in the braking distance. All these points must be taken into account while driving in the rain or when the air temperature outside the window is freezing.

Worn tires or flat tires can also be a factor in stopping distance. The more the rubber tread is worn out, the worse the grip of the car on the road. This fact should be taken into account during the period of off-season “re-shoes” of the car, since using worn-out tires, you save on your own safety. It is usually recommended to change tires once every 5-7 years, depending on the intensity of use and driving style.

Another factor, due to which the braking distance can increase several times, are worn pads, lack of brake fluid and other malfunctions of the brake system. If the driver reacted in time to a change in the road situation and managed to press the brake pedal, the task of the technician is to instantly transfer this force to the wheels of the car. Delaying even a split second can cause an accident, especially at high speeds.

How the braking distance differs from the stopping distance

Many motorists also mistakenly classify such concepts as the driver's reaction speed and visibility conditions on the road as factors affecting the length of the stopping distance. It is not right. Since the beginning of the braking distance is considered to be the moment when the wheels of the car began to actually slow down their rotation. A broader concept - the stopping distance just includes the time for the driver to make a decision about the need for emergency braking.

Thus, the stopping distance is the distance covered by the car from the moment the driver detects the danger until it stops completely. In other words, the stopping distance includes the reaction time of the driver, the response time of the braking system and the braking distance of the vehicle itself.

See also : Why when braking the brake pedal hits and what to do in such a situation.

How to calculate the braking distance of a car using the formula

Thanks to the collected statistics and its analysis, today we can approximately calculate the braking distance for a particular car, depending on its speed. For you can use the following formula:

  • Tn= Kt* V * V / (254 * Кsc)

In which:

  • Tp - vehicle braking distance;
  • Kt is the braking coefficient, which for a passenger car is 1;
  • V - vehicle speed;
  • Kss - coefficient of adhesion of the car to the road;
    • Dry road - 0.7;
    • Wet road - 0.4;
    • Snow - 0.2;
    • Ice - 0.1;

Note that the braking distance is directly proportional to the square of the speed. Therefore, every time you double your speed, the braking distance is 4 times longer.

For example, if the vehicle speed is 50 km / h and the road is dry, then according to the formula the braking distance will be 14 meters:

  • 1 * 50 * 50 / (254 * 0.7) = 14 m.

And at a speed of 100 km / h and the same dry road, the braking distance increases 4 times to 56 meters:

  • 1 * 100 * 100 / (254 * 0.7) = 56 m.

But be sure to take into account the fact that any calculations are only estimates and in a real situation, it is necessary to take into account dozens of accompanying factors that we wrote about above.

See also : Why the brakes on the car creak and how to fix it.