Driving assistance and safety

Active Brake Assist

Driving assistance and safety

Active Brake Assist

Keeping your distance. Staying ahead.

The image shows the Active Brake Assist in the A-Class.

Keeping your distance. Staying ahead.

The Active Brake Assist system contributes towards minimising the danger of a rear-end collision and mitigating the consequences of an accident.

The Active Brake Assist system contributes towards minimising the danger of a rear-end collision and mitigating the consequences of an accident.

Too small a distance between vehicles is one of the main causes of severe accidents. Active Brake Assist reduces the risk of collisions with a vehicle in front in three ways. And this is how it works:

  • Radar-based distance warning.
    A warning lamp lights up in the instrument cluster if the distance to the vehicle ahead falls below a pre-set value for several seconds within the speed range 30 to 250 km/h. If the distance continues to lessen at a fast pace, an intermittent alarm tone is additionally sounded.
  • Situation-specific brake boosting effect.
    On identifying a risk of collision with moving objects in the speed range from 7 to 250 km/h or with stationary obstacles in the range from 7 to around 70 km/h, situation-specific brake boosting can support the driver during emergency braking by generating additional brake pressure.
  • Autonomous braking.
    If the driver fails to take action in response to the visual and audible warnings, the system will initiate braking automatically. This already reduces the speed significantly. At low relative speeds, this braking manoeuvre is sufficient to prevent a rear-end collision. If drivers press the brake pedal during the autonomous braking manoeuvre, the situation-specific brake servo assistance is activated and decelerates the vehicle to a complete stop if the situation requires. Unlike the range of application of situation-related brake force boosting, autonomous braking in response to moving objects is only available up to a speed of 105 km/h – and in combination with Distance Pilot DISTRONIC up to 200 km/h.