YOUR mystery columnist asks why we need HS2, and has the common misunderstanding that the proposed line is about speed, when in fact it is all about capacity on the existing Victorian rail network.

We have three main lines in UK from the north to London; the West Coast Main Line via Manchester and Birmingham, the Midland Main Line via the East Midlands from Sheffield, and the East Coast Main Line via Newcastle and York.

All three are at or near full capacity, especially at their southern ends where more traffic concentrates as more local lines join these arteries as one nears London (which is why building HS2 starting in the south makes sense).

Most of this capacity is gobbled up by high speed non-stop trains, such as the West Coast Pendolinos.

For those to run at 125mph on a mixed-traffic railway means everything else has to ‘get out of the way’. These will be moved to HS2, freeing up to 75 per cent of the capacity on those classic lines.

So you don’t just get HS2 for your money, you also get 75 per cent more capacity on those three main lines to use for local trains and freight.

Reopening lines such as Leek to Stoke (currently mothballed), or improving the service to mid Wales and the Cambrian Coast and countless other rail-starved locales isn’t possible without HS2 because the core network cannot accommodate those extra trains.

So benefits of HS2 are far wider than the north – south corridor.

Vince Chadwick Wilmslow