Such circumstances can be especially hazardous for bus and coach travel, where even momentary loss of control could lead to potential rollover situations.

The new Scania ESP stability program contributes enormously to improving safety by monitoring key stability parameters and automatically triggering appropriate controls. It is designed to work on wet or slippery roads (the aim being to loss of control resulting from either oversteer or understeer conditions) and on dry roads (where the main risk is roll over resulting from excessive speed or adverse camber on bends).

The system has sensors that measure lateral acceleration at the vehicle’s centre of gravity. If this force exceeds a predetermined limit, the engine torque is cut and wheel brakes are applied. In extreme circumstances, full emergency braking may occur. 

The system is able to detect driver reaction by comparing the yaw angle with the steering angle. If these do not correspond, engine torque is cut and wheel brakes applied to stabilise the vehicle. Precisely which brakes are activated (on which wheels and which axles) depend upon the nature of the instability.

When ESP is triggered, data is stored within the system’s memory. Frequent triggering indicates a need for driver training.