The autobahn has a 'suggested' speed limit of 130 km/h (80 mph), a suggestion widely ignored by many Mercedes and Porsche drivers. They may suddenly appear out of nowhere, close behind, blinking their brights to move you out of their way.

On normal two-lane highways the limit is 100 km/h (62 mph). Cars towing trailers must stay under 80 km/h (50 mph).

In cities and towns, the speed limit (Tempolimit) is 50 km/h (31 mph) unless otherwise posted.

In the last decade or so, the '30-Zone' has gained great popularity. These are residential areas with a posted 30 km/h (18 mph) speed limit to protect children and pedestrians who live in the neighborhood.

Approaching a construction zone, you will see a series of speed limit signs, usually starting with 100, (62 mph) then another sign with 80 (50 mph), then another with 60 (35 mph). You can't resume speed until you see an end-of-speed-limit sign or a new posted speed.

Germany uses unmarked police cars and automated roadside radar/photo devices that take pictures of violators. Yes, you will see scofflaws who blatantly exceed the posted limit, but it can be expensive if you join them and get caught.

In Europe, including Germany; you will rarely see warnings like 'reduced speed ahead'. One minute you may be doing 130 km/h (80 mph), and suddenly you see a 110 (65 mph) limit sign. You are expected to pay attention to the posted limits.

A note on converting kilometers to miles:

Muliply the kilometers by 6 and move the decimal point 1 place to the left:
8 kilometers = 4.8 miles
12 kilometers = 7.2 miles
Speed limit 70 = 42 miles per hour