Starting in 1992, using DOS as operating system, the program has evolved from DOS to Windows with MFC, finally to LINUX and it is based now on ROOT. Have a look at Reiners Bähnle

Main features are:
Unlimited number of trains can be controlled simultaneously.
Collisions of trains will be avoided by an automatic train controller.
Trains run either according to a timetable or are controlled individually.

The velocity and the direction of movement (forward / backward) can be set for each train in a velocity dialog window.