The 2015 election campaign offered the electorate a choice of policies on HS2: The two major parties, plus the Lib Dems supported the project, the Green Party and UKIP opposed it. But it was a case of Hobson’s choice. In all likelihood, the new government will now claim that HS2 has been ‘endorsed’ by the electorate. The hybrid Bill will trundle on through its Parliamentary stages.

The project is not quite, however, home and dry.  All infrastructure projects take time to complete and large pieces of concrete and steel take a very long time; HS2 is extremely large, as one might suppose from the £50bn price tag.  Consequently, when the next election falls due (particularly if circumstances conspire for a short parliamentary term) the project will still have years to run before the first stage opens.  The second stage is pencilled in for a 2033 completion, time at least for another three general elections.

Over such a long time horizon, the world can change considerably, if not dramatically, such is the pace of technological progress. And there lies a major risk faced by the taxpayer when underwriting the huge cost of HS2, the prospect that by the time the first train runs, the project has become obsolete, a risk made worse by the commitment of vast quantities of poured concrete and welded steel to a very specific purpose.  It is this lethal combination of the time taken to complete projects and their specificity that makes infrastructure spending, so favoured by those who seek to manage the economy, such a poor tool for economic management.

One particular technology waiting in the wings with the potential to surprise is self-drive or autonomous cars. Google has been actively promoting the technology and four pilot schemes backed by government money are underway in various UK cities; in the last budget the Chancellor committed more funds for investigating the potential and a recent report envisaged that by 2030 a quarter of all cars sold would be fully autonomous. Both government and industry see this technology as important for the future of the nation’s car industry and wish to make the UK a world leader in the field.

For HS2, the risk is that autonomous cars impact significantly on current, all important business travel forecasts. If, in the future, the business traveller can be ‘chauffeured’ freely between London, Birmingham and Manchester, whilst undertaking all the office tasks they are able to do on the train (and more besides), this could very well tip the balance for many in their choice of travel mode.

Indeed, this technological challenge raises the intriguing possibility that the high-speed track should not be built for high-speed trains but become Britain’s first dedicated road for autonomous vehicles: a route along which platoons of electric or hybrid cars moving at high speed, whisk occupants between the south and the north; a twenty-first century clone of the M1.

Think also of the other advantages: a great deal of change left over from £50bn (no electrification or signalling required, no pricey train sets and no need for that expensive tunnel through to Euston Station), a much more visually pleasing prospect than a continuous, near-ground-level cross-country electricity transmission grid and probably a quieter prospect too. All circumstances more likely to meet less environmental opposition and to tempt the market once again to take the risk and fund the infrastructure needed; an outcome that is both innovative technically and entrepreneurially driven. That surely would be a worthwhile legacy for today’s politicians to leave behind.