Safety: More extensive assistance

Oct 20, 2014
When it made its debut, the B-Class redefined the standard of safety in the compact class with a variety of new driving assistance systems, some of which were included as standard equipment. These functions have now been enhanced and new assistance systems added to give the driver even more support. Automatic front-passenger airbag deactivation is capable of preventing incorrect operation.
The standard-specification COLLISION PREVENTION ASSIST PLUS extends the functionality of COLLISION PREVENTION ASSIST (radar-based distance warning and braking assistance in the form of Adaptive Brake Assist) with the addition of autonomous partial braking to reduce the risk of rear-end collisions. If the driver fails to act when a risk of collision is detected, despite the warning light in the instrument cluster and the intermittent audible alert, the system will automatically trigger partial braking. The vehicle speed is thus already significantly reduced. At low relative speeds, it may be that this intervention is sufficient to prevent a rear-end collision.
The drowsiness detection system ATTENTION ASSIST (standard) has been similarly upgraded: operating within an extended speed range (60 - 200 km/h), it now uses a five-stage bar display to visualise the driver's current attention level. The system's sensitivity can be varied via the "Assistance" menu in the instrument cluster. If the "Sensitive" setting is selected, the system warns the driver even earlier.
Automatic parallel and perpendicular parking as well as automatic exit from parallel parking spaces is made even easier with the further-improved Active Parking Assist with PARKTRONIC. This is because the system now provides assistance with active steering and braking intervention when manoeuvring into a perpendicular parking space. The electronic PARKTRONIC monitors the front and rear ends during manoeuvring and warns the driver if it detects a risk of collision.
An optional extra, Traffic Sign Assist, helps the driver to obey the traffic regulations - particularly beneficial when driving on long, monotonous stretches of road with variable traffic signs, through roadworks or in an unfamiliar town. Traffic Sign Assist is able to recognise speed limits and no-overtaking restrictions, as well as the end of such restrictions. This information is displayed in the instrument cluster and in the map view of the COMAND display. Having detected a traffic sign, the system sends out visual and audible warnings from the instrument cluster if the driver starts driving the wrong way down a one-way road, e.g. on a motorway slip road (wrong-way warning function).
Traffic Sign Assist displays any traffic signs identified in real time. The images seen by a camera located just behind the front windscreen are compared with and checked within split seconds against the signs stored in the system. At the same time, the system refers to the data provided by the navigation system.
Recently unveiled in the new C-Class, automatic front-passenger airbag deactivation is now optionally available also for the B-Class. A pressure sensor in the seat cushion allows the system to recognise whether the front passenger seat is occupied or if a baby seat or child seat has been fitted there. If this is not the case, the front-passenger airbag is automatically reactivated.
The B-Class now also features as standard a tyre pressure monitoring system, which uses sensors on the valves to monitor continuously the pressure of all four tyres. This measures tyre pressure and temperature under normal conditions and then in the event that conditions change. These data are sent by radio signal to an aerial in each wheel arch and transmitted from there to the control unit. Tyre pressure information is displayed in the multifunction display of the instrument cluster. After the car has been driving for a few minutes, the current pressure of each tyre appears in the "Service" menu. There is also a yellow warning light. If this light remains on, the tyre pressure in one or more tyres is significantly too low. A text message will also appear in the display in this case.
B-Class (W246) Lane Keeping Assist
B-Class (W246) Active Parking Assist
B-Class (W246) Traffic Sign Assist
B-Class (W246) ECO display
B-Class (W246) Adaptive Highbeam Assist