Btw, HS2 is eating an astonishing amount of the transport budget up (and these delays will extend this further):
Seeing it like that really brings home just how much of a drain HS2 is.
If the route via the M1 corridor
'Common sense' HS2. 300kph/190mph, but maybe 220kph/250kph until out of London and other tunnelled sections. Start at Kings X St Pancras (Or Euston if you must...), tunnel to near Cricklewood, then follow MML alignment to the north circular, there looks to be quite a bit of spare railway land anyway, then pretty much follow M1/MML alingment, with tunnels at places like St Albans as far Luton, where you tunnel, with maybe a Luton HS2 under the existing station. Then follow M1 towards Rugby. Birmingham/WCML route splits here keeping north of Coventry and then tunneled into Birmingham via the airport. Connection to Trent valley line near Rugby, with the next section to Crewe running along a similar alignment to existing Trent Valley line as the next phase. At Rugby eastern leg continues towards Leicester possibly using part of the old GC formation. This then gets extended in two stages, to Derby/Nottingham, and then onwards to Sheffield and Leeds.
A lot of industrial stuff has sprung up close to the M1, and this will bring less opposition than going through the Chilterns, if businesses are affected (slightly over?)compensate them properly and plan it to ensure business continuity. A lot easier than dealing with NIMBYs
Brings benefits to a much wider area than the current disaster.
If you could average 125mph/200kph end to end including one or two stops Birmingham would be 50 minutes ish from London, is there any benefit in trying to shave another 5 or 10 minutes off this?
Deploy boots on the ground to keep a rolling build going over the various extensions, start the Rugby - Crewe, then as the early design/build resources get released move them on to the next bit and so on.
I keeping hearing about all the studies done before the current project kicked off that 'picked' the best route, I am going to be polite and say they are rubbish given where we are now, you cant argue with the numbers.