Braking distance

Stopping Distance is the distance traveled from the driver's eager step on the brake pedal to the full stop of the car at a certain initial speed. Including reaction distance and braking distance in two parts. The smaller the braking distance, the better the braking performance of the car. Because it is more intuitive, it has become a widely used indicator to evaluate braking performance. Correctly understanding the braking distance of the car plays an important role in ensuring the safety of driving.

Tested according to national standards. Mondeo has good test results: The braking distance of 50 km/h to 0 is 12.4 meters, which is 6.6 meters shorter than the national standard. In actual driving, these meters may be life and death gates.

The time during which the driver is in motion, when the driver finds an emergency until the brake pedal is depressed, is called the reaction time. The distance the vehicle travels during the reaction time is called the reaction distance. The length of this distance depends on the speed and reaction time. The higher the travel speed or the longer the reaction time, the longer the reaction distance. The reaction time is directly related to the driver's sensitivity and technical proficiency. The usual reaction time is 0.75 to 1 second. If the vehicle speed is 30 km/h, the response time is one second and the reaction distance is 8.33 meters.

The braking distance refers to the distance that the tire appears on the road surface when the driver depresses the brake pedal and the vehicle stops completely. The length of the braking distance depends on the speed, braking force, and adhesion coefficient. The higher the travel speed, the longer the braking distance and the travel speed is proportional to the square of the braking distance. Braking force refers to the force that hinders and prompts the wheel to stop rotating after the driver depresses the brake pedal. The size of braking force, in addition to the stroke of the brake pedal, also depends on the adhesion coefficient between the wheel and the ground. The smoother the road (such as icy road), the smaller the adhesion coefficient and the longer the braking distance. Experiments have shown that the motor vehicle travels on different roads at the same speed and the braking distance is not the same. For example, a braking distance of 30 km/h on an asphalt road is 5.9 m, a braking distance on a snow drift is 17.7 m, and a braking distance on an icy road is 35. 4 meters.

The braking regulations in various countries all set the braking distance for various models at the prescribed initial speed. Vehicles that exceed this distance are unqualified vehicles and cannot be driven on roads. One of the most important indicators for traffic inspection by the traffic management department is the braking distance. China's requirements for braking distances for automobiles (at no load) are:

The braking distance should be measured by a professional using a special instrument. In the past, the method of stepping on the brake and dragging the tire was neither scientific nor accurate. When the braking distance does not meet the requirements, the brake system should be overhauled in time to prevent accidents.