I think rail travel in the UK is extortionally expensive; in order to get decent prices you have to book weeks in advance and get a very restrictive ticket. If I wanted to go to London at the weekend for some reason, then it would cost me (with railcard) £65 for a single, and about £85 for a return. Quite a while ago, my brother and I wanted to go to London to see an exhibition about Jimi Hendrix. The total cost of tickets came to over £150!
The government is trying to get people to use their cars less for less congestion/CO2/etc., even with the equally ridiculous cost of fuel it's usually cheaper to drive (not to mention more convenient). Consider families: take two adults and two children to Scotland from York for a short holiday and you're looking at £200-£300, without bring lots of stuff, bikes, etc., and they won't have a car when they get there.
Rant over. Sorry about that!