b) Emergency Brake System
The emergency brake system has to be operated in a graduated way as well. However, the vehicle driver can take one hand off the steering in order to do so. The deceleration achieved using the emergency brake system has to be at least half as big as the one prescribed for the service brake system. In this case, the hand and foot forces for the driver stated in the table below cannot be exceeded.
c) Parking Brake System
The parking brake system must be able to hold the loaded vehicle at standstill on a gradient of 20%, in case of trailer trucks, the towing vehicle coupled to a trailer or semitrailer should be held at standstill in a gradient of 12%. The maximum permissible hand or foot forces are shown in the following table.
In the parking brake system, power transmission should only take place mechanically. In most cases, the parking brake system at the same time takes over the job of the emergency brake system.