Databasedesign for Railway System

This is how i indent to design my database: (It is for a academic project)

Table Trains:
    TrainUID # primary key
    TrainNumber # Official train number do not need to be unqiue
    Traveldays # This is currently given as bitfield with a span over a year
    TrainType # ICE, RE, ...
    TrainZone # depending on where they run

Table Legs:
    LegUID # primary key
    TrainUID # foreign key to Trains
    RouteUID # foreign key to Route
    StartTime # Time when the train leaves i.e. 10:30
    EndTime # Time when the train starts i.e. 10:33
    TravelTime # Time the trains runs
    DwellTime # DwellTime at endstation

Table Routes:
    RouteUID # primary key
    StartStation # foreign key to Station, Station where the leg begings
    EndStation # foreign key to Station, Station where the leg ends

Table Stations:
    StationUID # primary key
    StationName # name of station
    StationLongitude # gps 
    StationAlditude  # coordinates

I need to make querys of the following type fast:

1. Select all legs where the train is of type X and in zone Y and runs on day Z and have a leg where the Name of the StartStation is W and the train has at least one leg which is (partly) between A time and B time (i.e. 8:00 - 12:00).


2. Select all legs from all legs which fullfil 1. and StartStation is Q and the StartTime is between C time and D time


3. Select all legs from all legs which fullfil 1. and RouteUID is G sorted BY StartTime

My Questions:

1. 
   

   Do you have any improvements?

   
   


2. 
   

   What database scheme would you recommend?

   
   


3. 
   

   How to implement the Traveldays?

   
   


4. 
   

   Query #1 is called only once and first, while Query #2 and #3 is called very often. Can you take advantage of the fact that #2 and #3 is always a subset of #1?