Those who built the Channel Tunnel never saw the low-cost era of airline travel coming. When the tunnel rail link, or HS1, opened in 1997, Brussels’ bureaucrats were busy putting the final touches to the Single Skies initiative, which created a common market for European air travel. It wasn’t long before Ryanair, easyJet and the other low cost carriers took off. Cheap and frequent flights throughout Europe diverted leisure travel from nearer shores (served by Eurostar) to farther flung places across the continent.  And the 20 million passengers a year scheduled to use the tunnel in the first decade of the 21^st century never quite showed up. Instead, the number has flatlined at 11million a year – making the tunnel something of a mixed success. Now, with HS2 edging further forward, history looks to repeat itself in another flawed mega project.

The problem with such big endeavours as the Channel Tunnel, and now HS2, is that they take a long time to plan and construct. In the meantime, the world has a habit of changing in unexpected ways. The first phase of the line (from London to Birmingham) is planned to open by the end of 2026; and the second (split) phase, to terminate at Manchester and Leeds, in 2033.  These opening dates assume, of course, that everything goes to plan and that the astonishing £60 billion budget isn’t derailed by unforeseen problems or economic and political uncertainty. Even if HS2 jumps those obstacles and is completed on time, the big question remains: will customers materialise in the numbers anticipated? HS2 is set to treble rail capacity in the West Coast line corridor. Yet given the revolution in self-drive technology, does Britain really need all this extra railway capacity?

After all, self-drive vehicles – once the stuff of science fiction – are no longer a pipe-dream. Vehicles today incorporate elements of it already; active cruise control – which reacts to the speed of traffic ahead – or lane-assist – which keeps vehicles on track – are both common in cars. So, too, are sleep detection systems and automatic parking. It’s true that the Holy Grail of self-drive technology – the fully autonomous vehicle – isn’t here yet. But with billions being ploughed into research and the likes of Apple, Google and Uber all joining the race, it’s a safe bet that fully capable self-drive vehicles (most likely electrically powered) will be on sale long before the London-Birmingham phase of HS2 opens. This begs the question: why would the traveller forego the convenience of his own robotically-chauffeured private car in order to make the effort of getting to and from a high-speed rail station?  There are good odds that HS2 will find itself facing a stalled or even declining market – hitting the buffers before it is even built.

Given the HS2 route has already been mapped out and with billions of taxpayers’ money earmarked for the project, is there a better way ahead? Why not anticipate the future by turning the HS2 route into a pathway used only by autonomous vehicles? Instead of taking up the equivalent of six lanes of motorway – as the HS2 route is scheduled to do – only four lanes would be needed. What’s more, costly electrification and signalling wouldn’t be needed – and nor, too, would rolling stock, stations and several tunnels. Billions could be saved. For half the cost of providing an HS2 service – which could be obsolete even as it opens – Britain can have a core super-highway network designed around autonomous vehicles. This would mean that the UK could lead the world, rather than merely copy the outdated high speed rail endeavours of elsewhere.

David Starkie is a former member of the Expert Advisory Panel for the Airports Commission and Senior Associate with Case Associates