[cheschire]

They could but german rail is already ridiculously crowded when factoring in all the safety regulations. Automation on the speed control already lets them pack the lines pretty tightly, which may be one reason why they've removed so much rail already.

Germans, in my experience, tend to be pretty rational folks. As much as the public likes to ream the decision makers for poor choices while armed with the perfect clarity of hindsight, my guess is they've gotten to this point because all the other choices seemed worse at the time they considered them.