The principle is that by constantly comparing the data, the micro-computer immediately detects if the operating speed of the brake pedal suddenly exceeds the usual measure, and thus deduces that there is an emergency braking situation. The control device takes the speed and the vehicle load of the bus into consideration. Also, the BAS microcomputer is connected by data bus to the control units of the electronic stability program (ESP®) and other connected systems such as the engine and transmission electronics. The BAS electronic systems "constantly learns while driving" so as to ensure optimum adaptation of the brake pressure in any braking situation.
It can happen at the critical moment: instead of braking to a standstill and keeping the foot on the pedal, the driver might brake fast, but not fast enough. In an emergency situation like this, the electronic brake assist system (BAS) is immediately activated. It interprets the driving behaviour and in the case of an attempted full brake application, it boosts the braking power to maximum in a split second.
Thanks to BAS the braking distance is considerably reduced. With an average gain in reaction time of 0.4 seconds, the reduction in the braking distance of a coach, assuming a speed of 100 km/h, can be up to 10 metres – which is a huge safety plus in emergencies.