The bus is one of the world's safest and most comfortable modes of transport. Innovations from Mercedes-Benz have made a decisive contribution to this – and make the OC 500 RF a pioneer on the road.
Traditionally, safety has always taken pride of place at Mercedes-Benz. All bus chassis are equipped as a matter of course with a highly-responsive, electronically-controlled braking system with disc brakes all-round, as well as with the anti-lock brake system (ABS) and the standard-fit Brake Assist function (BA). It boosts braking force to a maximum in fractions of a second in an emergency braking situation, thus reducing braking distances. The Electronic Stability Program (ESP®) with acceleration skid control (ASR) helps the driver to master critical handling situations.
Most accidents start long before the actual collision: with a lapse in concentration, poor visibility or hazards which cannot be anticipated. That's why the Mercedes-Benz safety concept employs a range of measures to support safe driving in everyday operations and helps you master critical situations.
Focus on safety.
SPA and AEBS.
Proven in the OC 500 RF touring coach chassis are the Lane Assistant (SPA) and the Advanced Emergency Braking System (AEBS). While the SPA warns the driver – by means of seat vibration – of an unintended crossing of the lane markings, the AEBS reduces the danger of driving into slow-moving vehicles or stationary obstacles ahead. If danger threatens, it initiates partial and full braking as part of an ascending scale of warnings, so as to avoid a rear-end collision or to reduce damage in the event of an accident. In this way, it reliably complies with the European regulations on automatic emergency braking.
The safety systems in detail.
Electronic Stability Program (ESP®).
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, dynamic driving situations, for example if the bus approaches physical limits when cornering. At the same time, the engine output is reduced. A possible "breaking-out" of the bus is thus prevented by the finely metered braking within the limits of the physical possibilities.
Among other things, ESP® monitors the lateral acceleration of the bus. If, on long bends – such as motorway exits – or with rapid lane changes, the bus reaches a critical driving situation, the vehicle speed is automatically reduced so the bus returns to a situation of driving stability. ESP® is comparable with the system installed in cars but provides additional functions adapted for use in buses.
Anti-lock brake system (ABS).
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 pressure variation. 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. Thanks to targeted electronic braking intervention, the wheels don't lock for long periods of time. 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).
Lane Assistant (SPA).
Lane Assistant (SPA) uses a camera located behind the windscreen to detect if the vehicle is in danger of leaving the road. SPA constantly monitors the distance of the bus to the lane markings on the road. If the vehicle crosses a lane marking, the driver is immediately warned by pulsating on the corresponding side of the seat. SPA is active at speeds of over 70 km/h and can be deactivated by switching on the turn signal, for example to initiate an intended lane change.
Advanced Emergency Braking System (AEBS).
The AEBS emergency braking system uses a radar system to detect both vehicles travelling ahead and stationary ones. It continuously determines the difference in speed relative to your own vehicle. If the currently driving activity and speed make a collision unavoidable if unchanged, the driver is warned first and the vehicle automatically initiates a partial application of the brakes. If the driver does not react and a collision becomes imminent, the vehicle automatically initiates a full application of the brakes. This can drastically mitigate the consequences of an impact.
Active Brake Assist 6.
The emergency braking system ABA 6 assists the driver by automatically initiating emergency braking if there is a risk of rear-impact collision with vehicles in front or stationary obstacles. It also detects moving or stationary persons and cyclists in front of the vehicle. The system reacts to this with an acoustic and visual warning to the driver as well as an automatically initiated partial braking or emergency braking.
With Active Brake Assist 6, accidents can be avoided even more reliably. The system covers the entire vehicle speed range and is active in the background. Up to a speed of 60 km/h, pedestrians and cyclists can react. The ABA 6 safety system reacts to crossing and oncoming pedestrians and moving cyclists in the vehicle’s own lane with automatic emergency braking. This automation also provides increased safety for cyclists, whether in intercity or urban traffic.
Sideguard Assist 2.
Sideguard Assist 2 is a safety assistance system that supports the driver in critical situations when turning right or turning left when visibility is possibly restricted. The system is designed to help detect moving obstacles within the system limits, and warns the driver so as to avoid critical situations or reduce the consequences of accidents when turning off or changing lanes.
The side areas of the vehicle are constantly monitored. As a result, vehicles, pedestrians or cyclists who may be in the blind spot are detected on both the front passenger side and the driver’s side. The radar system precisely detects the movements and warns the driver of possible collisions. The intuitive user interface and clear warnings allow the driver to drive safely and relaxed.
Rain-light sensor.
The rain sensor and automatic driving light are assist systems that activate automated functions by means of a sensor system and relieve the driver of routine tasks.
The light sensor increases road safety by automatically switching on the driving lights depending on the current lighting conditions and thus improving the visibility of the roadway.
Tyre Pressure Monitoring (TPM).
Tyre Pressure Monitoring (TPM) displays the current pressure in the individual tyres and warns of deviations from the optimum pressure. This reduces tyre wear, has a positive effect on fuel consumption and prevents dangerous tyre damage.
The right tyre pressure contributes to driving safety and significantly reduced fuel consumption. Even a tyre pressure set 0.5 bar too low can increase fuel consumption by up to 5%. The wheel electronics are positioned on the valve on the inside of the rim. The sensors record the data relevant to the tyre pressure and transmit it to the display instrument.