If you were building a high-speed railway out of London, you'd logically terminate it at the other end of the country, perhaps Newcastle (280 miles) or Edinburgh (405 miles). The point of higher speed is to shrink distance, to make the far near, and incidentally to encourage passengers to prefer rail over air travel. This is why the French TGV runs from Paris to Lyon (290 miles) and Marseilles (480 miles), and Japanese bullet trains from Tokyo to Osaka (320 miles) and beyond. Conventional trains currently do around 250 mph, so 300 miles looks like a logical benchmark, given likely future improvements in speed, for the first major stop on the line.
So why is HS2 being run to Birmingham, which is little over 100 miles from London? The suggestion that this will bring economic benefits to the West Midlands is piffle. 150 years ago railways were revolutionary because they allowed the faster movement of freight. The mainline to Birmingham allowed manufactured goods to be transported to markets in London and beyond more cheaply and quickly than the canals. Since the coming of modern roads and lorries, railways have largely been about passenger movement, which means that in economic terms their value is chiefly down to commuters. Occasional business travellers are no more significant in numbers than OAPs or tourists. The dominance of commuters means that the largest benefit of any line accrues to the larger destination, both through the increased centralisation of economic activity and by allowing employers to recruit from further afield. The key benefit to commuters is that they can take advantage of cheaper housing further out. The main benefit to the other end of the line is that more metropolitan wages are spent locally, so the real boost to the West Midlands economy will be in services and consumption (hairdressers and garden centres), not industrial regeneration.
The purpose of HS2 is to provide a shorter commute for people who work in London and wish to live in large(r) properties in Solihull. At present, and allowing for transfer time at either end, such a commute takes almost 2 hours. Post-HS2, it will drop to around 1 hour and 10 minutes, which puts it on a par with stops on the fringes of the Underground, such as Amersham. We're expanding the commuter belt further into the hinterland, not linking up previously isolated regions. The announcement of the clumsily-named phase 2 of HS2, which will extend the line to Manchester and Leeds, should be taken with a pinch of salt. I doubt these lines will ever be built because they won't be sufficiently attractive to London commuters, even if George Osborne wangles a station in his Tatton constituency. The unreality of the claims that this will benefit the North can be seen in the anticipated change in journey times. Newcastle will now be just over 2 hours away from London, which happens to be the current journey time to Liverpool. So all the prosperity Merseyside has enjoyed over the last 30 years will now be extended to the North East.
If we were serious about a high-speed rail link to the North, we'd use the existing M1 transport corridor (and the A1 corridor north of Leeds). This would not only be more direct, it would have less of an impact on the environment and existing housing, obviate the need for extensive (and expensive) tunnelling, and allow for greater use of Luton Airport to serve London, conceivably avoiding the need for a third runway at Heathrow. The only downside is that it wouldn't be as attractive to London commuters as a line through the Chilterns to the Forest of Arden. There aren't that many who would welcome a 1 hour commute just so they could live on Tyneside.
Our romantic obsession with railways, and the thrilling idea of high-speed travel, blinds us to the reality that trains are essentially commuter transport systems. The strategic investment in high-speed trains to bind a country together, as in Japan and France, should not distract from the fact that such networks ultimately serve the metropolis. Paris and Tokyo are dominant capital cities because of high-speed trains, not in spite of them. To believe that such a network in the UK will move economic activity out of the capital and into the regions is naive. HS2 phase 1 at least has the virtue that it makes this reality plain for all to see. They should just have renamed it the New Metropolitan line and had done with it.