Would it be very difficult to implement a train ? The tracks are there, the trains are there, the stations are there... Why shouldn't every 30 min. a train pass a station and hold for 5 minutes. Imagine the possibilities you can get with this. For this it would be helpfull to have a Station clock which runs according to the servertime.
It also would be nice to jump off the train, with the risk of braking legs or arms.