Rear fog light

On this Opel Corsa , the rear fog light is in the lower left corner of the bumper. For optical reasons, a dummy is installed on the other side of the vehicle.

A rear fog light is a particularly bright red additional light attached to the rear of the vehicle. Compared to the tail lights, it emits around 12 to 20 times more intensity. It is used to make the vehicle easier to see in heavy fog. Rear fog lights must be installed either symmetrically in pairs or individually in the center of the vehicle or to the left of it.

The rear fog light is an active safety instrument . Since it can dazzle the following traffic due to its brightness, its operation is restricted by strict regulations, which vary from country to country.

Use in Germany

In Germany, cars registered for the first time since January 1, 1991 must be equipped with a top speed of over 60 km / h and their trailers with one or two rear fog lights. Other motor vehicles (e.g. tractors, motorcycles) and trailers below 60 km / h may be equipped with a rear fog light. Retrofitting is not required for old vehicles. When importing cars from countries in which no rear fog light is normally installed, retrofitting is required as part of a so-called homologation .

use

Daihatsu Cuore with rear fog light in the bumper, so that the legally required ten centimeters distance to the brake lights is maintained

According to Section 17 of the German Road Traffic Act (StVO), rear fog lights may only be used in Germany if the visibility through fog is less than 50 m (Section 17 (3) sentence 5 StVO). In Germany, this is the distance between the delineator posts on the edge of country roads and motorways when the route is straight, which makes them suitable for determining visibility. The visual impairment must not be caused only by rain.

In § 3 StVO there is also the following provision on the maximum speed in fog: If the visibility is less than 50 m due to fog (the same requirement as for using the rear fog light), the maximum speed may be 50 km / h. Therefore, if the rear fog light is used correctly, a maximum speed of 50 km / h is permitted.

There is no usage ban in urban areas.

A control lamp with a yellow light in the dashboard is mandatory. Nevertheless, in practice it is often observed that drivers forget to switch off the rear fog light after driving through a foggy area. The improper use can be punished as an administrative offense with a fine of 20 euros. If there is a risk to other road users or even an accident due to incorrect use, the warning fee is 25 or 35 euros.

Opel Kadett with a reversing light in the rear light unit on the passenger side. The rear fog light is integrated in the unit on the driver's side.

In a train (vehicle with trailer (s)) only the rear fog lights on the last trailer need to light up. On the one hand, this saves electricity and, on the other hand, it reduces the glare that the tractor's powerful rear fog light would produce through reflections on the trailer. Switching off the rear fog lights on the towing vehicle or on the first trailer is only permitted if the respective switching off and on again takes place automatically by plugging in or removing the connector for the trailer lighting.

According to ECE R48, the rear fog light of the towing vehicle may be switched off when a trailer is operated. When attaching load carriers (e.g. bicycle carriers) with light units, it must be switched off to reduce glare. The automatic switching off and on again on the towing vehicle is implemented by

a mechanical switch-off contact in the trailer socket

the trailer control unit when the trailer is recognized (automatically).

a microswitch built into the trailer socket with an additional cut-off relay

Use in Switzerland

In Switzerland, the use of rear fog lights is not compulsory and only permitted under certain conditions. According to Art. 30 of the Swiss Traffic Regulations Ordinance (VRV), fog lights and rear fog lights may only be used if visibility is severely restricted due to fog, blowing snow or heavy rain.

literature

Jürgen Kasedorf, Richard Koch: Service primer for vehicle electrics . 15th edition, Vogel Buchverlag, 2007, ISBN 978-3-8343-3098-7
Rudolf Hüppen, Dieter Korp: Car electrics all types. Motorbuchverlag, Stuttgart, 1968, ISBN 3-87943-059-4
Hans-Hermann Braess, Ulrich Seiffert: Vieweg Handbook Motor Vehicle Technology , 6th edition, Verlag Vieweg + Teubner Wiesbaden 2011, ISBN 978-3-8348-1011-3