Radar Systems Take Over The Driving

2023 Author: Eric Donovan | [email protected]. Last modified: 2023-08-25 09:36

Drive 100 kilometers of the motorway without touching the pedals? This should be possible with modern distance assistants. In theory - because the test drive produced a different result.

By Sebastian Viehmann

Modern luxury limousines have a bit of James Bond character: Radar eyes behind the radiator grille or in the bumper discreetly eye the traffic, infrared or thermal imaging cameras turn night into day. Sophisticated distance assistants not only keep your distance from the vehicle in front, but also brake independently.

Many names for one technology

The “Distronic Plus” in the new Mercedes CL-Class, for example, works with the aid of two radar systems in a range of 20 centimeters to 150 meters and at speeds of up to 200 kilometers per hour. The so-called pre-safe brake intervenes when a rear-end collision threatens. But distance assistants and automatic braking systems are not only available from Mercedes. Ford offers an adaptive cruise control system ("Adaptive Cruise Control", or ACC for short) with a collision warning system ("Forward Alert"). Honda also has an ACC system ready for the new Civic. Then there is the CMBS (Collision Mitigation Brake System), which is supposed to help prevent rear-end collisions. BMW's cruise control system is also called ACC and works at speeds of up to 180 kilometers per hour. There is an optional "Stop & Go" function,which brakes the vehicle to a standstill. There is no automatic emergency braking, just as there is no Mercedes.

But: Can the distance assistants convince in an endurance test on the autobahn and country road? To find out, we drove in a Mercedes E-Class with Distronic from Paris to St. Petersburg. Operation is child's play: the desired speed (up to 180 kilometers per hour) is set with a small lever to the left of the steering wheel, and the desired distance to the vehicle in front with a knurled wheel on the center console. The vehicle in front becomes the “lead vehicle” on which Distronic orients itself: If it slows down, the Benz also brakes, accelerates it, and Distronic and Daimler rush behind. The term “towing vehicle” actually fits best in this context: You get the impression that the person in front is pulling you behind you on an invisible tow rope.

Problems with "gap jumpers"

This always works perfectly when the motorway is fairly empty and the speeds are halfway constant. In France, Poland or the Baltic States, for example, we could sometimes slide for an hour without even having to stroke the gas or brake. But as soon as the traffic gets denser, the driver is asked again. Since the system does not get any closer to the vehicle in front than the requirements of the safety distance allow, "gap jumpers" often put a spanner in the works. And as soon as you hit the brakes, the Distronic deactivates and you have to readjust it.

Especially on German autobahns, which are driven at very different speeds, one is also annoyed by the inertia of the system. Especially the acceleration is pretty tough. At least the Distronic ensures that you think about your driving behavior - because you often get the impression that you would be significantly below the minimum distance without the electronic spacer.

Helpless in the rain

In convoy traffic, where you normally have to be on the accelerator or brake, the Distronic provides a considerable gain in comfort. In principle, the system can also be used on country roads and in the city. On winding roads or on exits it can happen that the Distronic loses the «towing vehicle» from the electronic eyes. Then you'd better disable the system.

The Distronic was unwilling to work only once during a distance of more than 3000 kilometers: during a heavy rain shower. In such cases, a notice on the instrument panel indicates that the assistant is temporarily unavailable. The technology - the manufacturers of assistance systems emphasize this again and again - should not take the reins out of the driver's hands.

Finally, the interesting question is who is actually liable if there is an accident despite the assistance systems or if the electronics fail. With systems like ABS, this is not a problem: the "property control", as the lawyers put it so beautifully, lies entirely with the driver. The technology, so to speak, only optimizes what is the driver's responsibility: to put a full can on the brakes.

The driver remains responsible

With telematics-based assistance systems, things get more difficult. If the driver could not override it, he would lose control over his car, so to speak. That is why there shouldn't be systems such as automatic emergency braking for the time being.

Traffic judges also suggest that the driver should not rely on assistance systems when in doubt. In April of this year, for example, the Hamm Higher Regional Court ruled on a case in which a motorist was flashed at too high a speed. The driver resisted and stated that the cruise control in his car was defective. However, the court ruled that a driver is always responsible for maintaining the maximum speed - even if the cruise control is switched on and even if it should be defective.

So leaning back and relaxing while driving is not the order of the day. Even if the plus in relaxation and comfort is one of the main reasons why you spend money on assistance systems.