I'm finding this discussion really interesting. I think the point I most agree on is that cities are not great places for cars, and that a great aim should be to bring the modal share of other cities up towards London levels. As Bald Rick said, driving in Birmingham is easier than in London, but that doesn't mean that you couldn't attract people out of their cars with a significantly better public transport system. That probably means a lot of miles of tram tracks, maybe tram trains to better use existing heavy rail lines, better segregation of intercity and metro services, probably some kind of crossrail scheme etc. Very, very expensive, but would transform lives and invigorate cities, allowing swathes of busy streets to be pedestrianised.
Getting back to the question - that's why for my mind 'reopenings' are rarely the right answer or something to shout about, as they tend to be little rural single track branch lines operated by 2 carriage sprinters every hour. I wouldn't have thought that Okehampton has made a single household give up their car, as rural rail can never be flexible enough for that.
A new urban metro line, with a ten minute frequency and easy connections to a network similar lines to cheaply and efficiently whisk you around the city for work or leisure... Now I'm sold. Portishead and Blyth have elements of this, but it'd be even better if they could be part of a wider coordinated plan of major network and frequency enhancements.
