One of the best examples of air/train integration is Frankfurt, which has the high-speed trainstop underneath the airport. You are much faster on the train than

One of the best examples of air/train integration is Frankfurt, which has the high-speed trainstop underneath the airport. You are much faster on the train than getting into your car and you pretty much have an ICE going to Cologne, Hamburg or Munich (not sure about direct ones to Berlin), going every 45min or so.