Safe driving

Safe driving

Acceleration skid control (ASR)* prevents spinning of the drive wheels. Additional support in terms of safety is also offered by the electronic braking system (EBS). With it the stopping distance is significantly shortened, as the brakes are applied more quickly and precisely. Ensuring pre-emptive braking and manoeuvring in inner-city traffic are the Sideguard Assist* and the new Preventive Brake Assist* systems.

The Electronic Stability Program (ESP®) is an active system for increasing driving safety and stability. It makes a noticeable contribution to reducing the risk of skidding during cornering or evasive manoeuvres. This is achieved by specifically controlling the braking forces on each individual wheel in critical handling situations, for example if the bus approaches physical limits when cornering. At the same time the engine output is reduced. A possible "breaking-loose" of the bus is thus prevented by the finely metered braking - within the limits of the physical possibilities.

ESP® monitors, among other things, the lateral acceleration of the bus. If, on long bends – such as motorway exits – or during rapid lane changes, the bus reaches a critical driving situation, the vehicle speed is automatically reduced to the extent necessary for the bus to return to a stable handling situation. The ESP® is comparable to that used in passenger cars, but is adapted for use in buses thanks to specifically adapted functions.

ASR prevents the drive wheels from spinning. It does this in two ways. On the one hand, ASR minimises wheel spin through measured braking interventions. On the other hand, the torque of the engine is controlled via the "electronic accelerator pedal". Even at full throttle, the engine only delivers as much output in critical situations as the drive wheels can transfer – a big advantage for safety when pulling away and for driving stability.

When pulling away, the wheel rotational speeds and the torque acting on the drive wheels are monitored. The torque distribution is controlled so as to prevent wheel spin. Optimum power flow is thus always guaranteed.

ASR helps the driver to minimise the risk of the drive wheels spinning and consequently of the rear of the vehicle (rear-wheel drive) breaking loose laterally when accelerating. Especially with high-torque engines, ASR thus offers greater comfort and increased safety when starting off – especially on roads with differing degrees of grip.

How ABS works: there are sensors fitted on all four wheels which detect the rotational speed of each wheel and pass this information on to a central control unit. If the critical point of blocking the wheels is reached, the wheel is stopped at precisely that threshold by varying the pressure. The brake pressure can be increased and decreased numerous times in the space of a second.

When braking, all the forces acting on the wheels and the rolling behaviour are continually monitored. The braking forces acting on the wheels are distributed in such a way that no wheel can lock, and the steerability of the vehicle is preserved as far as possible.

In December 1970, Mercedes-Benz presented the world's first electronically controlled ABS – a revolution in driving and road safety. Using targeted electronic brake actuation the system prevents continuous blocking of the wheels. The risk of losing steering stability is minimised and, in the case of a full application of the brakes, the vehicle can be steered in the desired direction. ABS technology forms the basis for further developed electronic safety systems such as the Electronic Stability Program (ESP®) or the Brake Assist system (BAS).


The Preventive Brake Assist from Mercedes-Benz is the world's first active Brake Assist System for public city transport buses. The new assistance system warns the driver about a possible collision with moving pedestrians as well as with stationary or moving objects, and in case of an acute danger of collision automatically initiates a braking manoeuvre with partial braking. Warning cascade and brake application are precisely designed for use in urban traffic. In case of a threatening collision with pedestrians or with moving or stationary objects, the Preventive Brake Assist function warns the driver both visually, with a red illuminated triangle containing a vehicle symbol in the central display, and acoustically, while at the same time initiating partial braking. This brake application is held until either the driver intervenes or the bus comes to a stop. The Preventive Brake Assist feature is based on a new generation of radar technology: the radar sensor system constantly scans an area of up to 250 metres of the lane ahead of the bus and also operates reliably at night and under adverse weather conditions.

The Sideguard Assist cornering assist system significantly increases the safety of unprotected road users especially in cities, as it supports the driver in promptly identifying critical situation when turning. The system operates in multiple stages: in the first stage, it informs the driver, in the second stage it emits an additional warning. If a moving object is located in the monitoring zone on the side, an LED in the form of a yellow triangle goes on in the A0 pillar. It intuitively directs the driver's attention to the situation next to the vehicle. A warning also appears in the central display. If the driver initiates or continues an action that could lead to a collision, an additional warning is emitted: the LED flashes red at high intensity and thereafter lights up continuously. There is also a vibration warning issued in the driver's seat. Moreover, Sideguard Assist warns the driver about stationary obstacles in the bend ahead of the bus and can also perform the function of a lane change assistant, in which case it operates with the same cascade of warnings.


* Optional equipment
** Available as special equipment on the solo vehicle