In the past, when transport infrastructure projects have been chosen, the rate of return on investment has been taken into account. The sad truth is that projects around London typically show a greater return on capital so they win out.
I believe this present 'evil, wicked, corrupt' Labour government has tweaked the equation a bit to give the regions a better chance. But I don't know if this has had any impact yet.
At present, the booming London and SE economy 'subsidises' most, if not all, of the rest of the UK, which, on raw figures, makes Tennessee look prosperous. It is pretty advanced thinking to suggest that a huge investment in the regions could rebalance the economy and make everyone more or less self-sufficient.
Sadly, although many people bang on endlessly about 'patriotism' there is not the level of national unity in the UK that made it possible (for example) for Germany to invest gigantic sums in former East Germany to bring it up to scratch. But that is what we need.