Emergency brake is only used if it is absolutely necessary, and it is deployed extremely quickly. The braking speed – or retardation to use the correct technical term – is
about 7 m/sec2 , which is on par with what many passenger cars can manage.
In practice this means that the truck’s speed can be cut from 80 to 0 km/h in about 40
metres.
The system monitors the vehicles in front with the help of camera and radar technology and functions irrespective of whether it is sunshine, mist, fog or darkness. If
there is a risk of collision, the driver is alerted via gradually escalating light and acoustic signals. If the system does not detect a response from the driver, the truck automatically
starts braking gently. If the driver still does not respond, the emergency brake is deployed until the vehicle comes to a complete standstill. After a further five seconds
without any movement of the steering wheel or other reaction, the handbrake is automatically engaged, a safety measure to prevent the truck from rolling if the
driver is in shock or is unconscious. When the emergency brake is deployed, the brake
lights start flashing to warn vehicles to the rear, and when the truck’s speed drops to 5 km/h the flashing emergency warning lights are also activated.
Volvo’s system also functions on curvy roads and can differentiate between roadside guard rails and genuine obstacles such as vehicles including motorbikes. In order to gain the full benefit of the system, it is essential to
ensure that all functions, such as the ABS brakes, are activated on both truck and trailer.
Considering the short period that has passed since the introduction of emergency brake legislation, it will take some time before its positive effects are reflected in accident
statistics.
However, Volvo Trucks is convinced of thebenefits of the emergency braking system and other active safety devices.
