Kay (Tithe Barn Primary) sent in this solution:
The route to be followed is from the Train Yard to A - B - L - M - D - C - Q - R - E - F - N - O - K - J - I - H - G - S - P - return to Train Yard.
Thomas (Tithe Barn Primary) sent in a different solution, starting from the Train Yard and says:
The order could be reversed by starting in an anticlockwise direction:
P I J A B L K O H G S R E F N M D C Q Train Yard
Holly (from Bristol) sent in yet another solution:
UREKA! I have found out how to do the Rail Network. Does it go from the
Weiye took a different approach, starting from the middle: