In addition to Germany's near strict-liability laws, which mean a driver is virtually always at fault in case of accidents with non-drivers, I'd like to point out the following:
- Most of Germany's road system is non-Autobahn. People are used to driving with restrictions. And are going to be nervously looking about to slam into them with a 100+kph speed difference.
- If you drive faster than the recommended maximum (130-140kph) and there's an accident, regardless of who caused it, your insurance company will try to blame you to at least some degree.
- They drive regular cars, with regular 5 speed gearboxes, for the most part.
That all means Germans tend, as a rule, to not go much faster than normal highway speeds, and yet pay attention more than on other roads.