Some technologies seem to be perpetually touted as the ‘next big thing’ which will improve life if only politicians took investing in it seriously. Fusion and magnetic levitation trains are two that come to mind.

Yet other technological change rolls round remarkably quickly, leaving those same politicians scrabbling to catch up with its implications. The world wide web is the poster child for such changes.

That leaves me with mixed feelings about the ideas being touted to improve our public transport which I’ve been sifting through as party of my membership of the Liberal Democrat policy working group on public services.

From both inside and outside the party, there is a remarkable degree of innovation caution.

Lots of small idea to bring about incremental improvements, a fair number of big and expensive ideas which (their proponents argue) will bring matching big improvements, but little in the way of major technological innovation being touted.

Not even a demand from Lembit Opik that we make the Segway a central part of the country’s transport future.

In all that, I suspect people are being too cautious. I’m not about to be won over by tax breaks for hoverboards, but, ahem, the speed with which driverless cars are advancing means the transport world is likely to be very different by the time a big project like Crossrail2 or HS2 is completed.

Already driverless busses look set to make a serious debut in the UK by 2015, thanks to the Milton Keynes initiative.

They may therefore start appearing as a regular feature on those city’s roads before the next set of general election manifestos for the main parties even go to print.

Given the speed of their development on the one hand and the long development times for big transport projects on the other, I fear not just the party but those interested in transport more widely are trying to shape a future which, by the time it arrives, will be quite different from the one they are planning for.

Think just how quickly driverless cars have developed in the last five years alone – and then think how long it takes to get planning permission, let alone build or fit out, a big public transport project. Public transport plans now should already be factoring in the high likelihood of a near future in which cars no longer need humans to drive them.

Some of the benefits likely to accrue from this are brilliant – but do not require policy changes. A further improvement in road safety is likely for, as we have seen in other areas where automated machinery replaces humans in repetitive tasks, computers are more reliable, less sleepy and never drunk. Brilliant news for humanity (road deaths killed more people than genocides during the twentieth century after all), a useful saving for the NHS but not something with many knock-on policy impacts.

Other changes are likely to be more troubling. Think what a significant part of the local economy of some ethnic minority communities is provided by the minicab trade, for example. As mechanisation (driverless cars) drives out low-skilled workers (minicab drivers) there is no guarantee that the economic transition for those most affected will be smooth or quickly. The long-run benefits to us all may be immense, but as previous such mechanisations have shown, the short-run pain for some can be great.

There will also be a one-off regulatory requirement and opportunity as driverless cars start appearing, to set the rules under which they perform and before new entrenched vested interests and the inertia of history make change hard. For example, from day one the tax treatment of driverless cars could strongly encourage sharing, so that we move away from the situation where one of the most expensive items in many household’s expenditure is also an item left unused for large parts of the day.

It would make transportation cheaper and greener if cars were shared far more – but that also requires a psychological shift for which there is an opening when a new technology gets introduced.

Those are a mere couple of examples. But more and more it seems to me that transport policies which do not factor in driverless cars will be looking antiquated before the projects they contain are completed.

UPDATE – The French take on this is interesting, as Autonews reports: