This particular film is in the posession of the National Railway Museum and you may be able to see if you go to York.
Some films are with the BFI and some may be seen on "Screenonline" through an educational establishment which might include certain public libraries.
Otherwise, I guess you'll have to buy the DVD
http://www.lovefilm.com/search/resul...way+roundabout
Buy price £2.44 or rent
Incidentally you'll get a glimpse of the line next week on the BBC series "Five Days"