The new Mercedes-AMG SL: the driving assistance systems

Oct 28, 2021

With the help of numerous sensors, cameras and radar, the driving assistance systems monitor the traffic and the surroundings of the new roadster. If necessary, they can intervene at lightning speed. As in the new generations of the Mercedes C-Class and S-Class, the driver is supported by numerous new or enhanced systems. This means that in everyday situations the driver is able to drive more safely as the result of being relieved during speed adaptation, distance control, steering and lane changes. When danger threatens, the assistance systems are able to respond to impending collisions as the situation demands. The functioning of the systems is made visible by a new display concept in the instrument cluster.

The new assistance display in the instrument cluster shows comprehensibly and transparently how the driving assistance systems work in a full-screen view. The driver can see their car, lanes, lane markings and other road users such as cars, trucks and two-wheelers in an abstracted 3D way there. The system status and operation of the assistants are visualised in this depiction of the surroundings. The new animated assistance display is based on a 3-D scene generated in real time. This dynamic, high-quality representation makes the operation of the driving assistance systems transparent as a tangible augmented reality experience.

The following are the most important innovations of the systems in the new SL:


This system included as standard is able to recognise typical signs of drowsiness and driver inattention, and displays a warning message prompting them to take a break. 

Active Distance Assist DISTRONIC

This intelligent system can automatically maintain the preselected distance to vehicles ahead on all road types - motorway, country road and in the city. New features:

  • Collision-preventing response to stationary road users at up to 100 km/h (previously 60 km/h)
  • Selection of the DISTRONIC dynamics in MBUX, independently of DYNAMIC SELECT 

Active Steering Assist

This helps the driver to stay in lane at speeds up to 210 km/h. New features:

  • Lane detection additionally with 360-degree camera,
  • Significantly improved availability and performance on bends on country roads
  • Improved lane centring on motorways
  • Situation-specific off-centred driving (e.g. formation of an emergency corridor, but also orientation using the edge of the carriageway on country roads without centre markings). 

Traffic Sign Assist

In addition to conventionally signposted speed limits, this recognises overhead gantries and signs at roadworks. New features:

  • Stop sign warning function – warning when about to run a stop sign
  • Red traffic light warning function - warning when about to run a red traffic light. 

Active Lane Keeping Assist

In a speed range of 60 to 250 km/h, Active Lane Keeping Assist uses a camera to detect when road markings or road edges are crossed, helping the driver to avoid leaving the driving lane unintentionally. The system also intervenes if there is a danger of collision with detected road users in the adjacent lane, e.g. with overtaking or oncoming vehicles. New features:

  • The reaction to edges of the carriageway, for example a grass verge,
  • Particularly intuitive steering intervention
  • Adjustment of sensitivity via a menu (early, medium, late) 

Active Lane Change Assist

Active Lane Change Assist cooperatively assists the driver in changing to the adjacent lane. The lane change to the left or right is only supported if, according to the sensor system, the adjacent lane is separated from your own by a broken lane marking and no vehicles have been detected in the relevant safety zone. New features:

  • the longer search phase (15 seconds instead of 10 seconds, depending on the country) in which the lane change can take place, and
  • the higher lateral dynamics (depending on country) 

Active Emergency Stop Assist

Active Emergency Stop Assist brakes the vehicle to a standstill in its own lane if it recognises that the driver is no longer responding to the traffic situation for a longer period. This works in the new SL even if Active Distance Assist DISTRONIC with Steering Assist is not switched on. Further innovation: Belt tensioning and braking jerk as a final signal of impending braking action

Active Brake Assist with cross-traffic function

Active Brake Assist uses the on-board sensors to register whether there is a risk of collision with vehicles travelling ahead, crossing or oncoming. The system can give the driver a visual and audible warning if a collision appears imminent. If the driver's braking response is too weak, the system can also assist by increasing the brake pressure as the situation demands, and also initiate autonomous emergency braking if the driver fails to respond. New features:

  • The turning function (including crossing pedestrians when making a turn),
  • Extension of the cross-traffic function to interurban routes (up to 120 km/h instead of 72 km/h)
  • Warning and braking if there is oncoming traffic 

Active Blind Spot Assist and exit warning function

Active Blind Spot Assist can give a visual warning - and if the indicators are operated also an audible warning - of potential lateral collisions in a speed range from around 10 to 200 km/h. If the driver ignores the warnings and still tries to change lane, the system can take corrective action by one-sided braking intervention at the last moment if the speed exceeds 30 km/h. When the vehicle is stationary, the exit warning function can warn against exiting because a vehicle (or even a bicycle) is passing within the critical area. This function is available when the vehicle is stationary and up to three minutes after the ignition is switched off. New features:

  • Reinforcement of the warning by the active ambient lighting (including the exit warning)
  • Thanks to the cameras of MBUX Interior Assist, a danger warning can already be given if the driver or front passenger merely move a hand towards the door handle.

DIGITAL LIGHT with projection of warning symbols onto the road surface

The revolutionary DIGITAL LIGHT headlamp technology is on board as standard in the SL models. It enables innovative functions, such as the projection of guidelines or warning symbols onto the road. DIGITAL LIGHT has a light module in each headlamp with three powerful LEDs whose light is refracted and directed with the help of 1.3 million micro-mirrors. The resolution is therefore more than 2.6 million pixels per vehicle. The micro-mirrors occupy the same area as a thumbnail. A control unit with a powerful graphic processor uses an HDMI-like connection to generate a continuous video stream to the mirrors. DIGITAL LIGHT therefore uses the technology of video projectors. The new headlamp can be recognised by its concave lens.

Highbeam Assist is highly accurate in masking out oncoming traffic or traffic signs. The light-dark boundaries and the light distribution of all other adaptive light functions are also realised with significantly improved precision, which optimises illumination in fog light, motorway light or city light, for example.

The assistance functions are revolutionary:

  • Warning of recognised roadworks by projecting an excavator symbol onto the road surface
  • Aiming a spotlight at pedestrians detected at the roadside as a warning
  • Traffic lights, stop signs or no-entry signs are pointed out by projecting a warning symbol onto the road surface
  • Assistance on narrow road lanes (roadworks) by projecting guidelines onto the road surface
  • Indication of the start of the cooperative lane change
  • Warning and directional guidance when Lane Keeping Assist or Blind Spot Assist detect a hazard 

Preventive occupant protection PRE-SAFE®

The Mercedes-AMG SL offers the unique PRE-SAFE® preventive occupant protection already as standard. In dangerous situations, PRE-SAFE® tightens the driver's and front passenger's seat belts as a precaution, for example, or moves the front passenger seat to a more favourable position in a possible collision. PRE-SAFE® uses the sensor technology of other systems such as ESP® or the driver assistance systems for this purpose.

The safety of little ones has also been taken into account: Child seat attachments according to the i-Size standard with Isofix anchorages and TopTether are located on the rear seats and on the front passenger seat. To ensure that the front passenger airbag is deactivated for safety reasons when small passengers act as co-pilots, an automatic child seat recognition system is installed on the front passenger seat: A mat integrated into the seat surface detects whether a child seat is fitted based on the weight distribution. Special child seats with transponders are therefore not required.