Not sure whether any agree, but would the money to be spent on this not be better spent in reopening Beeching-closed lines and/or subsidising proper integrated rail/bus links for towns not served by rail, including through ticketing (essentially an extension to PlusBus which is valid outside the urban area)?
Is it so desperately important to get from Manchester to Leeds in 30 mins when many sizable towns throughout the UK have no rail link at all? If there's a capacity issue why not just lengthen the existing Manchester/Leeds trains to say 12 carriages?
That said, for purely selfish reasons I wouldn't mind seeing some sort of spur from HS2 down towards central southern England to relieve the painfully slow and overcrowded links from this part of the world to the north... though even that I would place as lower priority than reopening lines as discussed above. I see social need as the big issue when it comes to improving public transport.
I think the priorities should be:
- creating an integrated timetable and fares system for all modes of public transport, infrastructure investment and journey time improvements should be made where the timetable requires
- improving buses and light rail in cities
- improving capacity and speed of Intercity links where significantly slower than by car / where there is limited capacity
- reinstituting links which would benefit the network as a whole such as East-West Rail
- reinstituting rail services which would serve significant populations (towns over about 15 000 - 20 000 people such as Wisbech and Haverhill in East Anglia - both 30 000+)
- closing the least used stations and building new stations where significant numbers of people live
- electrification and new rolling stock
- reducing the number of ticket types and encouraging walk-up travel for modal shift away from cars
I think Manchester - Leeds could be an important corridor to invest in because of the number of flows it would affect. Door-to-door journey times across the Pennines are typically noticeably longer by rail than by car and a combination of reducing journey times over the core section, better connections and affordable, integrated walk-up fares could attract many people to public transport. But I agree that without an engineering study, a price and proposed network timetables with and without the new route, we can't know whether it's worthwhile. We also haven't tried putting on much longer trains.