Jarrutusta

Jarrutusta is Finnish for braking, the act or process of slowing down or stopping a vehicle. In everyday language it denotes the use of brakes, while in technical contexts it refers to the engineering and safety aspects of stopping a moving machine.

Most passenger vehicles use hydraulic braking systems that apply force to wheel brakes via brake fluid. Modern cars typically combine disc brakes at the wheels with a brake booster for easier pedal feel. Many systems also include an anti-lock braking system (ABS) that prevents wheel lock during hard braking, and electronic stability control (ESC) to help maintain steering control. In electric and hybrid vehicles, regenerative braking can convert part of the kinetic energy into stored electrical energy, reducing the reliance on friction brakes.

Jarrutusta can occur in several forms: service braking, where the driver applies the brake pedal; emergency braking, which uses maximum brake force for a rapid stop; and engine braking, which slows the vehicle by downshifting or reducing engine power without heavy pedal pressure.

Factors affecting braking include tire grip, road surface, weather conditions, vehicle mass, and brake temperature. Wet, icy, or uneven roads reduce friction and increase stopping distance. Brake fade from overheating can temporarily reduce braking efficiency, especially after repeated heavy braking on long descents.

Stopping distance combines reaction distance and braking distance. Roughly, braking distance grows with the square of speed and depends on the coefficient of friction between tires and the road. Practically, safe driving requires adequate following distances and appropriate speed for conditions, along with regular brake maintenance.