Americans drive more, so if you want to compare the safety of the two systems it is better to look at deaths per vehicle-km. Germany has 4.2 deaths per billion vehicle-km. The United States has 6.9.
But driving is inherently dangerous, that's the whole point. America shouldn't be let off the hook for partaking in more of a dangerous activity, as if that makes it less dangerous. If Americans don't want to die in cars they should drive less. (Trains would help.)
