A common cry amongst politicians in the run up to the general election has been the need for infrastructure investment.
Our would-be leaders have been falling over themselves to spend other-people’s money.
There are, after all, only two ways of ultimately paying for something. Either the taxpayer funds the ‘investment’, or the user does.
So, given that not government but people will end up footing the final bill one way or another, how should we determine which investments are worth making and which are not, especially when it comes to transport schemes such as building a railway, widening a motorway or adding a runway?
The mechanism used is modelling. Taking different factors, giving them varying levels of importance, throwing them together in a complex formula and seeing what comes out.
But as economists point out, modelling is easy, the hard bit is deciding what assumptions, the weight attached to different inputs for example, the modelling should be based on.
Some suggest the whole thing has just been made harder because we are at a uniquely difficult point for predicting future travel. But are we?
Not uniquely – the last hundred years have seen some massive technological changes that have in turn transformed the opportunities we have for travel, not just in the vehicles we travel in or the infrastructure we travel on but in the impact of smart phones and contactless payment systems. But difficult, yes.
There is more upheaval on the near horizon. Take the automation and electrification of cars for example. Unshaped by political will, the most common influence on infrastructure provision, and how and what uses it, is the market.
When will driverless cars become commonplace? Not simply when the technology becomes available but when people decide they want it, can afford and at a price that providers can make money from.
The part politicians play is laying out a vision of what the future might look like. They set the parameters. In transport we see, for example, many councils declaring climate emergencies and implementing policies which promote certain types of travel and dissuade others. Ultimately people and industry will have to frame their own investment decisions on the policy of the day.
All of which makes modelling future transport demands challenging. Therefore, it is helpful, indeed necessary, to ask the question: what is the goal we are trying to achieve and consequent to that what is needed to make it come about?
Of course, this is not an exact science. It requires us to recognise the multiple interdependencies within and beyond the transport sphere. It forces us towards ranges of outcomes and away from single ‘point’ numbers that create the impression of precision way out of step with reality.
And it perhaps reminds us that dry cost-benefit calculations are far better suited to informing decisions about alternative schemes than determining whether any one particular scheme makes cast-iron economic sense.
While investment in infrastructure has a warm, reassuring ring to it – who could object? – it has to be investment for more than investment’s sake. It must relate to the view that we have of the world we want to live in and ultimately that is what the politicians need to be telling us – their hopes for the future, not their shopping lists.