If people are waiting for transport and miss the rail, the next one comes, and the next on comes... but I have never missed one because of terminal congestion. You might run a few minutes late if you miss your rail, but people don't have the authority to stall the entire system. The German rails are especially well known for running on time and on schedule. The rail arrives to pick you up the same time, everyday, and brings you home the same time, everyday.
You can't say about the highway system.