Virtually no other area inspires the Mercedes-Benz engineers to produce such consistently impressive results as much as research into new safety technologies. The first important safety milestone was reached back in the 1950s with the development of the passenger safety cell, invented by Béla Barényi. Today it is just one of many components of the Integral Safety Concept which edges Mercedes-Benz vehicles ever closer to our vision of accident-free driving.
The majority of 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 operation and to help you bring critical situations under control.
DISTRONIC PLUS proximity control uses cutting-edge radar technology to scan the situation in front of the car and to keep the desired distance. It plays a major role in minimising the risk of rear-end collisions by recognising potential dangerous situations and reacting appropriately.
As the sensors can operate in a range between 0.2 and 180 metres the system is also helpful in city traffic or stop-and-go traffic. If necessary, it can brake the vehicle to a full stop and also accelerate again. DISTRONIC PLUS proximity control is only available in conjunction with the optional 7G-DCT dual clutch transmission.
In stop-and-go traffic, DISTRONIC PLUS applies the brakes automatically – if necessary, until the vehicle comes to a complete stop. Automatic braking is applied with a deceleration of up to 4 m/s² As soon as traffic allows, DISTRONIC PLUS automatically accelerates to the set speed.
Should DISTRONIC PLUS register that heavier braking is required, an intermittent warning tone is sounded and a warning symbol lights up in the instrument cluster. This alerts the driver to pay close attention and apply the brakes if necessary. To start off again after a full stop requires nothing but a simple pull on the cruise control lever or a tap on the accelerator.
Using a camera the range of the low-beam headlamps and high beams are regulated in such a way that the road is illuminated as best as possible, regardless of the driving situation and the preceding motorists. The high beam automatically switches on when no other road users are detected. A special feature is the gentle transition from one type of light to the other without an abrupt change in intensity.
In critical braking situations, specific criteria such as brake pressure and road speed are used to activate the adaptive brake lights if necessary. When activated, the brake lights flash to give drivers behind even better warning of the risk of a rear-end collision.
Studies have shown that motorists' reaction time for initiating a braking manoeuvre is shortened by up to 0.2 seconds if a red flashing warning light is activated in place of the conventional brake lamps during emergency stops. At a speed of 80 km/h this translates into a stopping distance shortened by about 4.40 metres. The brake lamps flash at a frequency of about three Hertz (if equipped with incandescent bulbs) or about 5 Hertz (if equipped with LEDs). These frequencies have proven especially effective in tests.
As soon as the vehicle travels at less than 10 km/h or has come to a stop, or if Brake Assist is no longer active and the vehicle deceleration rate drops below 6.5 m/s² for 150 milliseconds the brake lamps will light up steady again.
The adaptive brake lights are triggered when:
The ATTENTION ASSIST function is particularly helpful on long journeys and when driving at night; the system warns the driver if it detects signs of failing attention and increasing weariness. This driving assistance system can warn the driver when it identifies typical signs of fatigue, which in turn improves handling safety.
ATTENTION ASSIST continuously analyses driving behaviour and steering movements. If the system detects certain steering patterns that frequently accompany drowsiness, it warns the driver visually by displaying the "coffee cup" symbol in the instrument cluster at the same time as emitting audible signals. ATTENTION ASSIST can be activated and deactivated in the main menu of the instrument cluster under "Assistance systems". When switched on, it is active at speeds between 80 and 180 km/h.
The bi-xenon headlamps are a further development of the familiar xenon headlamps, offering xenon technology for both low and high-beam. LEDS are used for the daytime running lamps, the indicators and the side lights.
The light source is a gas-discharge lamp in which an arc is generated in a quartz cylinder containing a mixture of gases. A single gas-discharge lamp is used for both the main and the low beam for each headlamp. The entire beam is used for the main-beam setting. When switching to the low-beam setting, a shutter is inserted between the lamp and the lens, blocking out the portion of the beam directed into the distance.
The tail lights, indicator lamp and licence plate lamp also use LEDs (the brake lamp, reversing lamp and rear fog lamps use conventional bulbs).
The ADAPTIVE BRAKE system improves ride comfort and safety by helping to perform critical braking manoeuvres more safely using the basic function of the anti-lock braking system (ABS). At the same time, comfort functions support the driver in everyday operation.
In critical situations, the Electronic Stability Program (ESP®) can help to stabilise the vehicle by applying a braking force to individual wheels and by adjusting engine performance.
If the ESP® system detects a critical situation, it applies the brakes systematically to one or more wheels according to the situation. Should the system consider it necessary, it will also make an automatic adjustment to engine torque. In this way ESP® helps the driver to stabilise the vehicle within the laws of physics – particularly when cornering and during sudden evasive manoeuvres.
The Intelligent Light System – as an active component of the safety concept – ensures the best possible visibility in all weather conditions and the most diverse traffic situations. When encountering oncoming traffic, in curves, fog or on free stretches of road the system adjusts to the situation adapting the characteristics of the light individually.
Too small of a gap between vehicles is the main cause of severe accidents. The radar-based collision warning system COLLISION PREVENTION ASSIST can enhance safety and driving comfort by warning the driver of following too closely and can support the driver's braking when it detects danger.
The B-Class was the first Mercedes-Benz in its segment to employ a radar-based collision warning system. The system can recognise insufficient gaps between the own vehicle and objects travelling in front at speeds of more than 30 km/h. When the system detects the danger of a rear-end collision it can issue a visual and acoustic warning to the driver.
If the system detects a danger and the driver applies the brakes at the same time, Adaptive Brake Assist can intervene for good measure: It then provides precisely the right amount of brake pressure that is needed ideally to avoid an impending collision. COLLISION PREVENTION ASSIST is an innovative component of the Integral Safety Concept of Mercedes-Benz.
Lane Keeping Assist can warn the driver if the vehicle begins to leave its lane unintentionally. A series of three vibrations of the steering wheel, imperceptible to the other vehicle occupants, serves as the warning signal. The system can recognise manoeuvres during which drivers leave their lane intentionally - when cutting a corner, for example - and will not issue a warning unnecessarily.
The Blind Spot Assist can detect vehicles in the blind spot and give the driver a visual warning in the form of a red triangle in the exterior mirror. Should the driver nevertheless activate the indicator, despite this visual warning, an audible warning is also triggered. The system is active from speeds of 30 to 250 kilometres per hour. Under 30 kilometres per hour a yellow triangle indicates that the system is inactive.
Mercedes-Benz stands for automotive safety. That's why our vehicles can support their passengers even in critical driving situations, so that every journey is as safe as it can possibly be.
The anti-lock braking system (ABS) enhances driving safety, especially when braking for hazards. During braking the anti-lock braking system reduces wheel lock-up by modulating the braking pressure of the individual wheels. This ensures that the vehicle remains directionally stable and steerable while maintaining the greatest possible braking power. In other words: ABS allows the driver to brake and steer simultaneously – allowing precise evasive manoeuvring – in order to avoid an accident.
The acceleration skid control (ASR) ensures that the wheels do not spin when accelerating. Especially when moving off on snow, ice and loose chippings, the acceleration skid control prevents individual wheels from spinning and the vehicle from sliding out to the side.
The system uses speed sensors to monitor the slip characteristics of the wheels. If the system senses a wheel is starting to spin, the acceleration skid control corrects the wheel speed by braking and intervening in the engine management system, thus reducing the wheel slip and wheel spin.
Brake Assist can detect emergency braking situations based on the speed with which the brake pedal is depressed and assists the driver by increasing the brake pressure. The system interprets a certain speed at which the brake pedal is depressed as an emergency situation, and automatically builds up maximum braking power within fractions of a second.
Brake Assist is integrated into the Electronic Stability Program ESP® and uses its technology for regulating brake pressure, eliminating any need for additional components. A sensor permanently monitors the speed at which the brake pedal is depressed and transmits this data to the electronic control unit.
If an unusually high pedal speed is registered, the system concludes that there is an emergency braking situation. The system then helps the driver to perform an emergency stop by automatically increasing brake pressure in the wheel brake cylinders. ABS continues to precisely meter the braking power up to the slip threshold, which ensures that steering control is maintained. Once the driver releases the brake pedal, automatic brake boosting ceases immediately.
When the PRE-SAFE® system detects the typical risks of an accident, it can activate preventive safety systems depending on the driving situation and vehicle equipment. These can help to reduce the risk of injury to the vehicle occupants.
The PRE-SAFE® system is able to recognise an impending accident because it represents a synergy of active and passive safety features unique to its vehicle class: it systematically accesses the sensors of existing systems such as ESP® or BAS , which are able to detect typical critical driving situations and provide the appropriate information to the PRE-SAFE® system, which thus supplements the safety systems fitted as standard.
Examples include securing of the driver and front passenger in their seats at an early stage by electric belt tensioners to prevent undesirable body movements and almost complete closure of the side windows and sliding sunroof to protect occupants from any objects entering the vehicle.
Cars from Mercedes-Benz have a host of safety systems to prevent accidents. Should the worst come to the worst, however, a number of occupant safety measures can be activated. They include protection for the vehicle occupants as well as for other road users.
The airbags for the driver and front passenger provide protection for the occupants’ head and torso in a collision, and also afford additional stability to the entire body. They are thus able to mitigate the severity of injuries sustained in an accident. If the crash sensors detect a collision of a certain intensity and direction, the airbags are deployed.
For this, a current impulse is sent from the control unit which ignites the kneebag’s initiator, which in turn ignites a solid propellant. The gases which are released in this way fill the airbag. The gases are subsequently expelled from the side of the airbag, away from the occupants.
The gas generators of both airbags work in two stages. The two stages are activated according to the degree of deceleration registered. Depending on the predicted intensity of the impact, the first stage of the gas generator is initially activated and the airbag only partially filled (60 percent for driver and 70 percent for front passenger). If a higher impact intensity is foreseen, the second stage of the gas generator is activated after a slight delay and the airbag is completely filled.
The ISOFIX child seat attachment system is a quick, convenient, non-vehicle-specific system conforming to ISO standards. It allows quick and easy child seat attachment in the rear. Its fixed anchorage points ensure a high degree of protection in the event of an accident.
A special ISOFIX child seat engages in the attachment points housed in the lower area of the backrest. This creates a rigid connection with the vehicle structure, meaning that seat movements caused by slack or incorrectly fitted seat belts can be avoided. TopTether is an additional safeguard that is attached at a point behind the rear head restraints. It further reduces the risk of the child seat tilting forwards in the event of a crash.
The kneebag on the driver’s side helps to protect the legs during impact and also stabilises the entire body. It can thus help mitigate the severity of injuries sustained in an accident. If the crash sensors detect an accident from a certain direction and that exceeds a given severity, the kneebag can be activated, together with the driver airbag and the belt tensioner.
The sidebags in the rear are stored behind the wheel arch lining. When they are deployed during a side collision they provide potential protection for the chest area of the rear-seat passengers.
They are triggered when the central control unit and the side satellite sensors register acceleration or deceleration forces acting on the vehicle in excess of a certain threshold. The sidebags deploy at chest height between the vehicle side and the occupant.
In the event of side impact of sufficient force, the windowbag deploys to cover the side windows and reduce the risk of the occupant’s head hitting the side of the vehicle or being hit by objects penetrating the vehicle interior. The windowbag is triggered simultaneously with the front sidebags and always on the side of the vehicle involved in the side impact.
When deployed, the windowbag spreads across the side windows between the A-pillar and C-pillar. The windowbag covers a large part of the surface area at the side.
The windowbag offers the following advantages:
To reduce consequential damage after an accident and support the work of the rescue services, a number of different actions are initiated, depending on the type and severity of the accident:
If an accident should occur the crash-responsive emergency lighting makes it easier for the vehicle occupants to be rescued and supports the efforts of rescue workers.
After a short delay the interior and footwell lighting (footwell lighting only for the driver and front passenger seats, in conjunction with optional Light and Sight package) can switch on and provide the occupants with a better sense of orientation; together with the hazard warning lamps, engine shut-off and door-lock release, they can facilitate rescue measures.
Mercedes-Benz has also published multilingual rescue guidelines (accessible worldwide on the internet) as a source of information for rescue services.
 Only available in conjunction with the automatic 7G-DCT dual clutch transmission. Component of the Intelligent Light System. Component of COMAND Online. Component of the optional Lane Tracking package; only available in conjunction with Becker® MAP PILOT or COMAND Online.