Djikstra a la C

Hey all.
I'm trying to learn some OS programming (C) in linux RH9 kdevelop.

I need to figure out how to make a simulation of a railway going through a single track with 5 waiting tracks on each end.

Track segments represent resources, Trains represent processes or threads (haven't decided which yet).

I plan on using semaphores on the waiting track "queue", but I'm not sure if I'm going the right way.

Should I use a multidimensional array to represent the track segments? Should I use Posix threads or processes and is it fairly easy to implement semaphores?