Some problems with ERD

Hi Guys,
I am a first year business student and our teacher has given us a scenario to create ERD from. I have came up with a design but I am a bit confused. It would be fantastic if I could get your opinion whether it is correct or not or if somebody could point me to the mistakes I am making. I have attached my diagram to this post. Here is the scenario:

"The American Railway Co has 19 routes in US most of which offering at least two departures each day. To cover all these routes, the company has many trains. Some trains are always assigned to the same route but most trains cover more than one route. Most trains have different classes: economy, business, and first class. Some trains have only one class.

Some routes have many departures each day. Each departure is assigned a train some of which only have economy seats while others offer all classes.

Customer selects the departure, the system shows the available categories on the train. The customer selects his preferred category and the system provides the price for the trip. "

I would really appreciate your help.
Best Regards,
John