Securing an accident scene: Robot in action: warning triangle 4.0

Sep 9, 2019

"Be careful on the A8 Stuttgart-Munich autobahn, there is an unsecured accident scene just after Stuttgart airport" – everybody has heard similar traffic reports. There is a high risk of secondary accidents. With innovations such as a small robot that automatically emerges from the rear of the vehicle after an accident or breakdown, and puts out a warning triangle at the roadside, the ESF 2019 shows how securing the scene of traffic hazards might be further improved. Other ideas are a warning triangle that folds out of the vehicle roof at the same time, and the rear window as a communication surface. This can be used to display messages such as "Help is on the way for other road users.

Correct positioning of the warning triangle can be vital for one's own safety and that of other road users: a driver drawing attention to a traffic hazard at an adequate distance and in good time can prevent potentially serious accidents. In Germany and in most EU countries it is compulsory to carry a warning triangle in the car[1]. ECE Directive R27 defines the requirements for a warning triangle. These include minimum values for visibility by day and night. An ECE-tested warning triangle must also withstand a wind speed of 60 km/h for three minutes.

But how is a warning to be given in the future, when there are also driverless and automated vehicles on the roads? Who will put out the warning triangle in this case? The ESF 2019 gives two possible answers to these questions – alongside car-to-X communication, which is already able to warn other road users electronically:

  • When a corresponding hazard occurs, a small robot automatically emerges from the rear of the vehicle. The warning triangle is immediately unfolded when the robot leaves the vehicle.
  • The vehicle's roof is also fitted with a warning triangle. When the robot leaves the vehicle, this opens out and warns other road users from an easily visible position. As a practical advantage, it is permanently integrated into the roof structure, and cannot be forgotten.

If the ESF 2019 is not driving in automated mode, both functions can also be activated individually by the driver.

At the same time the rear window is used as a communication surface to secure the scene. Messages such as "Help is on the way" can be displayed there, so that other road users do not stop unnecessarily. Further examples of the projection of warnings onto the rear window can be found in the section on cooperative environmental communication.

Safety measures also after an accident

In the case of complex accidents with multiple collisions or rollovers, it may not be possible to put up a warning triangle either by robot or on the roof. The hazard warning system may also be out of action. Especially at night, this poses great danger for other road users: they might overlook the unlit vehicle and collide with it at full speed.

To lower this risk the ESF 2019 has electro-luminescent emergency lighting. The special paint used (for details of the technology see the section on PRE-SAFE®) is applied as strips on the front bumper, on the sides of the body and between the light clusters at the rear. The advantage is that even after an accident causing very severe damage, the illuminated vehicle remains visible.

Already today, numerous measures in Mercedes‑Benz vehicles help to ensure that consequential damage can be reduced and the rescue of occupants is assisted. As soon as a protective system (e.g. belt tensioner or airbag) is triggered, an emergency or service call is made or a breakdown is detected, the following measures can be initiated depending on the type and severity of the incident:

  • Automatic activation of Mercedes-Benz emergency call to notify emergency services of the location and emergency situation and initiate rescue. Data transfer is via a communication module with its own SIM card.
  • If necessary, deactivation of the high-voltage supply (in electric vehicles)
  • Activation of the hazard warning system to secure the scene of the accident and protect occupants from a follow-on accident.
  • Activation of the interior lighting to help occupants and rescue services find their bearings.
  • Slightly lowering the front side widows if an airbag has been deployed – this ventilates the interior and helps the occupants to find their bearings
  • Opening of the central locking system to facilitate access to the interior for helpers.
  • Raising of the electrically adjustable steering column; facilitates exiting and access to the driver.
  • Sending a recognised breakdown or accident situation by car-to-X communication and to the Mercedes-Benz Service Centre (Mercedes me or service call) to warn of accident or broken-down vehicles and automatically offer the driver contact with the Mercedes-Benz Service Centre
  • A rescue sticker provides a direct link to the vehicle's rescue data sheet. For this purpose there are QR code stickers in the fuel or charging flap and on the opposite B‑pillar. In an emergency, first responders can scan the QR code with a smartphone or tablet PC, which quickly and reliably allows access to the correct rescue datasheet and makes a rescue easier
  • Apart from rescue datasheets, the Rescue Assist App for smartphones and tablets has three-dimensional views of the vehicle –also offline if no mobile network is available at the scene
  • An innovative emergency helper uses the media display to give important safety information, as breakdown, emergency and accident situations can be highly stressful for the occupants. For example, it tells them where the first-aid kit can be found. It reminds them to wear their safety vests, and explains how to release the seat belts if the vehicle is lying on its roof after an accident. It can also mute the audio system automatically.

[1] Incidentally, § 15 of the German traffic regulations (StVO) prescribes that with "fast-moving traffic", the warning triangle must be positioned at least 100 metres from the scene. Naturally local circumstances must also be taken into account. If the accident scene is e.g. around a bend or behind a dip or the brow of a hill, the warning triangle must be positioned a greater distance away. Since 2014 is has also been compulsory to carry a fluorescent jacket for each occupant in the car, and this must be worn in the event of an accident or breakdown.