German road conditions in general are excellent, although you should exercise caution while traveling on older roads in eastern Germany. Contrary to popular belief, there are posted speed limits on large stretches of the highway, or Autobahn, mostly when traveling through urban areas or when the road has many curves. The high speed permitted on the Autobahn, adverse weather conditions, and unfamiliar road markings can pose significant hazards. Driver error is a leading cause of accidents involving U.S. citizen motorists in Germany.
Bicycles are another cause of mishaps. Many German streets and sidewalks have dedicated bike lanes. Whether you are driving or walking, be aware that bicycles have priority use of these lanes. If you are walking, watch for bicyclists before crossing or stepping into bike lanes. Bicyclists also have priority over cars when turning onto side streets. If you are driving, check whether a bicyclist is approaching from either direction before attempting to enter side streets, even when the light is in your favor. If you are turning into a side street and hit a bicyclist using a marked bike lane, you will be held responsible for any injury or damage caused.
Driver right-of-way rules are different from the United States. Unless you are traveling on a priority road, vehicles coming from the right have the right-of-way. It is generally illegal in Germany to pass vehicles on the right.
The threshold for determining whether a person has been driving under the influence of alcohol is lower than in the United States. Under German law it is illegal to operate a vehicle if the blood level is 0.5 per mill or higher. The law imposes a penalty and the withdrawal of the driver's license for specified periods of time depending upon the gravity of each violation.
It is illegal to use your cell phone while driving in Germany.