Electronic Stability Control (ESC)

Also referred to as electronic stability program (EPS) or on trailers “roll stability program” (RSP).

Sensors measure steering angle, yaw angle, lateral acceleration and wheel speed. The systems electronic control unit compares these with a set of values and decides whether action needs to be taken to stabilise the vehicle. This can involve reducing engine power and braking individual wheels. The cost: typically between £1200 and £2000.

For buses and coaches over 5 tonnes ESC will become mandatory for most new type approvals on 1 November 2011, and most newly registered vehicles on 1 November 2014. These deadlines conflict with the European Commission for Europe deadlines in its Regulation 13 covering braking systems, which also makes ESC mandatory. The UK has yet to decide which deadlines will apply.