Mercedes Benz

The B-Class provides its drivers with comprehensive support and protection by means of numerous driving assistance systems, from drowsiness detection with ATTENTION ASSIST to proximity control with DISTRONIC PLUS. These assistance systems, which have been the reserve of higher vehicle segments to date, are based on state-of-the-art radar, camera and sensor technology and are designed to address the common causes of accidents, such as inadequate distance, fatigue and darkness.


As a world first in the compact segment, the B-Class features a radar-based collision warning system with adaptive Brake Assist as standard, which can lower the risk of rear-end collisions. The COLLISION PREVENTION ASSIST system is able to output a visual and acoustic warning to alert a distracted driver and prepares Brake Assist for the most precise possible braking response. This is initiated as soon as the driver emphatically operates the brake pedal.

In contrast to systems currently on the market in the compact class, the new COLLISION PREVENTION ASSIST feature is not merely a system intended to minimise minor damage in urban traffic. Rather, this innovative solution is aimed at protecting motorists from typical rear-end collisions in dangerous traffic situations.

Mercedes-Benz expects the new safety system to have a significant positive effect on accident statistics. On the basis of detailed analyses of accident data, Mercedes-Benz safety experts assume that around 20 percent of all rear-end collisions can be avoided with this radar-based technology, while the severity of such accidents can be reduced in a further 25 percent of cases.

Electronic helpers: all the other assistance systems at a glance

The democratisation of safety also encompasses an array of other assistance systems which have been adopted into the B-Class from the larger model series. These include:

- Adaptive Highbeam Assist: when vehicles are detected ahead of or oncoming to the vehicle, this system automatically dips the beams and adjusts the range of the headlamps appropriate to the distance. The driver benefits from a longer dipped beam range and does not generally need to switch manually between high and dipped beam.

- Blind Spot Assist: this radar-based system employs two additional radar sensors in the rear of the vehicle to warn the driver before a lane-change if it detects another vehicle in the exterior mirror's blind spot.

- Lane Keeping Assist: a camera behind the windscreen recognises clear carriageway markings and outputs a warning if the car is about to leave its lane unintentionally.

- ATTENTION ASSIST(standard): warns drivers when it detects typical signs that they are over-tired. Studies have shown that around a quarter of all serious motorway accidents are caused by drowsy drivers, making this factor an even bigger cause of accidents than drink-driving. With ATTENTION ASSIST, Mercedes-Benz is therefore making another important contribution towards helping to avoid accidents: it employs high-resolution sensors to observe driver behaviour and can recognise whether the driver is tired or not paying attention, based primarily on steering wheel movements.

- Speed Limit Assist: a camera fitted behind the windscreen detects speed limit signs at the roadside and compares this data to information contained in the GPS system or the digital map. The relevant speed limit is then displayed in the instrument cluster.

- Brake hold function: when stopping, for example at traffic lights, the driver merely has to press the brake pedal slightly more firmly. He can then take his foot off the brake pedal and the brake will remain engaged until he moves off again. The brake is released automatically when the driver steps on the accelerator.

- Hill Start Assist: this function is able to prevent the vehicle from rolling back unintentionally when moving off on an uphill slope.

- Reversing camera: the B-Class is optionally available with a reversing camera incorporating a wide-angle lens which is integrated in the handle strip on the tailgate. When reverse gear is engaged, the image from the camera is transmitted to the screen of the Audio 20 system or the COMAND system. Static and dynamic guide lines assist the driver during manoeuvring.

- DISTRONIC PLUS: the radar-based adaptive cruise control supports the driver at speeds between zero and 200 km/h by maintaining the distance to the vehicles in front. In doing so it is able to apply the brakes to bring the vehicle to a complete standstill and also accelerate it again. As a result, the system is also particularly convenient in stop-and-go traffic. If the system detects that the distance is being reduced too quickly, it warns the driver with both visual and audible signals.

A number of assistance systems which provided for added comfort and safety in the previous B-Class are also optionally available for the new generation. These include:

- Cruise control with SPEEDTRONIC: the cruise control function of the speed control system maintains the preset speed. The additional SPEEDTRONIC function ensures that the stored speed is not exceeded. Both functions come as standard with the 7G-DCT dual clutch transmission and are optionally available for the models with manual transmission.

- Active Parking Assist: two ultrasonic sensors installed on the right and left of the front bumper measure the length and depth of a potential parking space. If the parking space fits, the driver is shown an arrow next to the "P" symbol in the instrument cluster. The optimum path into the space is calculated on the basis of the vehicle's present position and the system assists the driver during the parking manoeuvre by operating the electromechanical steering. The driver is still required to perform acceleration and braking, however. The speed is limited to 10 km/h for the parking manoeuvres.