After five minutes on the famed autobahns, you get a full realization of the often quoted "you are more likely to die from an auto accident than an airplane accident" or "commercial flying is safer than driving".
First of all, the lanes are a bit undersized. For a saloon car, there is about a meter left on each side for most parts of the network.
Next, the traffic is heavy! This is probably due to the complete lack of tolls. If you are on the outer lane to pass another vehicle, you have less than 10 seconds to complete your job, because that is the time when another vehicle will come charging down behind you.
Tailgating is dangerous, but at the same time you hate to be traveling too "slowly". So passing often is a necessary evil. And it is a sheer act of terror. Most of the time, it is necessary to pass at about 130kph. At that speed, and with a high sided truck about a meter next to the right, the fluid mechanics sent my rental car slightly airborne each time.
|Two diagonal lines across 130 means the speed limit is no more 130kph!|
Driving on the autobahn is a super high workload activity. You have to stare with 100% concentration at the car in front, and at five times a second, you have to compare each 2D image of the back of the car in front with the previous image to compute and determine whether you are closing in. If the car is about 200m ahead, and you are driving at 120kph, you have about one second of reaction if the car in front suddenly slows down.
It is not infrequent that traffic comes to a sudden and complete standstill. I was driving eastward from Hanover on the E30 on July 16, 2014. Suddenly, about 500m in front, all the lanes were filled with stationary vehicles. I slowed down, switched on my hazard lights switched them off immediately after two blinks. The driver behind me imitated me, and that was when he made a near fatal mistake. He did not switch off his hazard lights. Apparently, he then signaled right, but because both of his turn lights were blinking, the car in the right lane was not aware he wanted to ease right. There was a loud bang, both cars nearly disintegrated and vehicle parts were flying everywhere.
If I was any closer the flying debris would make me part of the accident, and my holiday would be disastrously ruined. It would be an international accident, with my car rented out of Amsterdam. It would take months or years to determine culpability. Even if Hertz were to act immediately, it could take easily a week for them to send a replacement car from Holland.
The traffic jam in front of me, unrelated to the accident behind me, cost me almost two hours of delay. It was apparently caused by a major accident involving trucks.
I drove for a week in Germany, and every other day, there was a jam of about an hour duration on the autobahns.
When I entered France from Saarbruken, the situation changed suddenly. The French motorway was nearly deserted (the toll from the border to Paris cost €30), and it was a pleasure to be able to drive at your own speed, without having someone in front holding you up, and without the fear of me holding somebody else up.
The above is totally my personal experience. The statistics on the Wikipedia link suggests that the German autobahns are better than most other places.