Hello,
Though I am more familiar (experienced) in PIC, hence Arduino, the Raspberry Pi vs Arduino is a question of what you have in hand and how much time do you have at your disposal.
There is a good example of model of controlled railway, including hardware, coding and connection steps.
http://www.penguintutor.com/projects/modelrailwayautomation
After several personal trials, I have went through it as well.