It is so amazing!!! The German autobahnen are famous for being some of the few public roads in the world without blanket speed limits for cars and motorcycles. Lack of blanket speed limits does not appear to negatively impact the road traffic safety compared with motorways in other countries; motorways are safer than other road types.
Certainly, speed limits do apply at junctions and other danger points, like sections under construction or in need of repair. Speed limits at non-construction sites are generally 100 km/h, 120 km/h, or sometimes even 130 km/h; construction sites have a usual speed limit of 80 km/h but may be as low as 60 km/h or even 40 km/h. Certain stretches have separate, and lower, speed limits used in cases of wet lanes.
Some limits were imposed to reduce pollution and noise. Limits can also be put into place temporarily through dynamic traffic guidance systems that display the according traffic signs. If there is no speed limit, the recommended speed limit is not more than 130 km/h, referred to in German as the
Richtgeschwindigkeit; this speed is not a binding limit, but being involved in an accident driving at higher speeds can lead to being deemed at least partially responsible due to "increased operating danger" (
Erhöhte Betriebsgefahr). The average speed traveled on the autobahn in unregulated areas by automobiles not regulated by other laws is about 150 km/h. On average, about half of the total length of the German autobahn network has no speed limit, about one third has a permanent limit, and the remaining parts have a temporary limit for a number of reasons.
In places without a general limit, there are mostly also no restrictions on overtaking (except for the general prohibition to overtake on the right side). Therefore, those traveling at high speeds may regularly encounter trucks running side-by-side at only about 80 km/h. In theory, trucks are not allowed to overtake others unless they drive 20 km/h faster than whomever they are overtaking, but truck drivers are generally under pressure to arrive in time, and such laws are rarely enforced for economic and political reasons, as many trucks are from foreign countries. The right lane of a typical autobahn is often crowded with trucks, and too often, trucks pull out to overtake. In some zones with only two lanes in both directions there is no speed limit, but a special overtaking restriction for trucks and/or cars pulling trailers. (An exception is Sundays and national holidays, on which trucks usually are not allowed to drive before 22:00 h, except for trucks carrying perishable goods and certain other exceptions such as military vehicles.)
Powerful modern cars can easily reach speeds well over 270 km/h (170 mph), and most large car manufacturers follow a
gentlemen's agreement by electronically limiting the top speed of their cars to 250 km/h (155 mph) for safety reasons (inexperienced drivers and risk of tires failing, especially when underinflated). Yet, these limiters can technically be defeated, so speeds over 300 km/h (190 mph) are not uncommon. But due to common speed limits and other traffic, such speeds are rarely attainable. Most unlimited sections of the autobahn are located outside urban and densely populated areas. The A 8 between Stuttgart and Munich is one such example, the A 4 between the metropolitan area of Chemnitz-Zwickau and Dresden as well. The A 81 between Stuttgart and Singen (Bodensee) is another example. The largest part of this route has no speed limit (about 150 km/90 mi).
Vehicles unable to attain speeds in excess of 60 km/h are not allowed to use the autobahn. Though this limit is not high for most modern vehicles, it prevents very small cars (e.g. quads) and motor-scooters (e.g. Mofas) from using autobahnen. To comply with this limit, several heavy-duty trucks in Germany (e.g. for carrying tanks or cranes) have a design speed of 62 km/h (usually denoted by a round black-on-white sign with "62" on it). There is no general minimum speed but drivers are not allowed on German roads to ride unnecessarily slowly disturbing traffic.