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.
For safe driving, the Mercedes-Benz safety concept supports you using many different measures: the control and display system is especially tailored to the driver. Then there are systems which are designed to alert and assist the driver in critical situations.
DISTRONIC PLUS proximity control helps the driver to maintain a specified (timed) distance from the vehicle in front when travelling at speeds of 0 to 200 km/h.
With BAS PLUS Brake Assist in conjunction with the PRE-SAFE® brake system head-to-tail crashes can be prevented even more effectively. If the radar sensors detect there is a risk of crashing and the driver applies the brake, BAS PLUS is primed to apply braking in accordance with the situation.
If a potential collision is identified within the speed range 30 to 200 km/h and the driver fails to apply the brakes sufficiently early, the PRE-SAFE® brake system emits visual and audible signals. If the driver does not respond to this warning, independent partial braking is activated approx. 1.6 seconds before the calculated impact at a deceleration rate of up to 4 m/s2. If there is still no reaction from the driver, an independent full brake application can be initiated automatically 0.6 seconds before what is considered an unavoidable impact.
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 drivers’ brake-activation response times are shortened by up to 0.2 seconds when emergency braking is indicated by a flashing red warning signal instead of conventional brake lights. At a speed of 80 km/h, this reduction in response time corresponds to a reduction in stopping distance of approximately 4.40 metres. The brake lights flash with a frequency of approx. 3 Hertz (with bulbs) or approx. 5 Hertz (with LEDs). Tests have shown this frequency to be particularly effective.
As soon as the vehicle is moving at less than 10 km/h or has come to a stop, or Brake Assist is no longer active and vehicle deceleration falls below 6.5 m/s² for 150 milliseconds, the brake lights light continuously again.
The adaptive brake light comes on 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.
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 standard-fit ADAPTIVE BRAKE system improves ride comfort and safety by helping to perform critical braking manoeuvres more safely with the basic function of the ABS anti-lock braking system, while convenience functions support the driver in everyday driving situations.
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. In curves, fog or on free stretches of road the system adjusts to the situation by adapting the characteristics of the light individually.
Brings light to the darkness: in "country mode", the light from the low-beam headlamps is distributed in such a manner that the edge of the carriageway is significantly better illuminated than with conventional headlamps.
Increases dynamically: the motorway mode is automatically activated in two levels: from 90 km/h the system increases the output of the bi-xenon lamps. From 110 km/h the setting of the headlamp on the inside of the traffic lane also changes to uniformly illuminate the entire width of the lane for a distance of up to around 120 metres.
In extreme weather conditions: with the enhanced fog lamp function the system improves visibility when fog is present. The left-hand bi-xenon headlamp pivots outwards and the light cone is simultaneously lowered. This light function is automatically activated as soon as the rear fog lamp is switched on if the vehicle is not travelling faster than 70 km/h.
Follows the driver: the active light function follows the driver’s steering angle: sensor data on the steering angle, yaw rate and vehicle speed allow the bi-xenon headlamps to pivot to the side in fractions of a second as soon as the vehicle is steered into a bend. With the "cornering light" function the cornering lamps automatically switch on when the driver activates the indicator or turns the steering wheel. The Adaptive Highbeam Assist gives outstanding visibility at night as well, without dazzling oncoming traffic or vehicles ahead.
Helps improve the vehicle’s own visibility: the LED daytime driving lamps make it easier for other road users to spot the vehicle and the integral headlamp cleaning system minimises dirt build-up on the lights. In addition the front position lights and tail lights, the indicator lamp and licence plate lamp also use LEDs.
Mercedes-Benz stands for automotive safety. That's why our vehicles can help their passengers even in critical driving situations, so that every journey is as safe as it can possibly be.
The PRE-SAFE® preventive occupant protection system can recognise critical driving situations and, if necessary, pre-emptively activate reversible safety systems to help reduce the risk of injury to the vehicle occupants. To do this, PRE-SAFE® permanently monitors sensor data from systems such as the ESP® and BAS, and can thus, for example, recognise vehicle over/understeering as well as emergency braking.
If a typical critical driving situation is detected by the system, the electromotive belt tensioners can be activated, the passenger seat with a memory function can be moved to a better position for impact (only in conjunction with the optionally available Memory package) and the side windows can be closed automatically, all in fractions of a second.
A host of safety systems work together in the SLK Roadster to prevent accidents. Should worst come to worst however, a number of different safety measures come into play. They include protection for the vehicle occupants as well as for other road users:
The active bonnet can reduce the risk of injury to pedestrians and cyclists. If the system identifies a collision, the rear section of the active bonnet rises up by approximately 85 millimetres using spring force. This produces additional deformation space to absorb the impact energy of the upper body of the pedestrian/cyclist at an earlier stage.
The airbags for the driver and co-driver 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, the airbags are deployed.
The gas generators of both airbags can be activated in two stages. Both stages are activated depending on the braking force applied. Depending on the predicted severity of the impact, the first stage of the gas generator is initially activated and the airbag only partially filled. If a higher severity of impact is predicted, the second stage of the gas generator is activated after a slight delay and the airbag is completely filled.
The headbags in the doors can help protect the seat occupant's head and reduce the severity of possible injuries in the event of a side-on collision. If the crash sensors detect an impact from a certain direction and surpassing a predetermined intensity, the airbags are triggered. These airbags are deployed synchronously with the sidebags and on the side on which the impact occurs. When deployed, the headbag covers the side window and together with the sidebag offers optimum protection. Thus in the event of a side-on impact exceeding a predetermined level, the risk of head contact with the side of the vehicle or against intruding objects is reduced.
The sidebags for driver and passenger help to protect the body in the event of a side impact. They stabilise the entire upper body and can help to reduce the severity of injuries.
They are triggered if the crash sensors register acceleration or deceleration forces acting on the vehicle in excess of a specific threshold. The sidebags deploy at chest height between the side of the vehicle and the occupant.
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:
 Part of the optional Driving Assistance package Part of the optional COMAND Online multimedia system Standard equipment for the SLK 55 AMG; available as part of the optional Dynamic Handling package for all other models