Amsterdam used to have a line to Amstelveen that ran trams and metros on the same track. The main disadvantage is the different platform heights, so you got ver

Amsterdam used to have a line to Amstelveen that ran trams and metros on the same track. The main disadvantage is the different platform heights, so you got very long platforms, half at tram height and half at metro height. I think they stopped it. As far as I know, Amsterdam's tram, metro and train lines are entirely separate again. They may still have some connections, but if so, those aren't used for regular service. As for the through problem, the main problem here was that many cities were already big before trains were introduced, and most didn't want to demolish large chunks of the city to make space for trains to the center (although American cities infamously later demolished their city centers to make space for cars). Amsterdam was on a big waterfront, however; the original 15th century port that wasn't being used anymore. The port moved east, and a new island would host the new central station right in the heart of the city. Although the city did lose its view of the waterfront. Edinburgh drained a lake to make space for the train station. And of course some cities did demolish houses to make space for trains.