Behaviour change — For what purposes, in what circumstances, and whose responsibility?

A NUMBER OF TRANSPORT POLICY ANNOUNCEMENTS in the last few days have focused attention on the issue of behaviour change and in particular how a different modal split in travel patterns by individuals in various circumstances might be beneficial, and where action to that end that should sit within the overall public policy making framework.

How can interventions with that intent be justified, designed and appraised within broader strategic decision-making, and what are the particular circumstances in which such approaches are appropriate?

The situations in question include the decision -making for the second runway and expansion at Gatwick Airport, theoretically linked to a limit on car use to address the surface access consequences ; plans for the new generation of new towns and how to make them less car-dependent, and the outcomes from introducing Low Traffic Neighbourhoods and any impacts on car use they may achieve.

In all these situations and others, a key question is how substantive and convincing is the case for, and commitment to, bringing about change, whether this involves any degree of restriction or coercion on individual choices in the broader public interest, and where the responsibility lies to specify and drive the intended change and to be held to account if it is not achieved. In essence, we are looking at a multi-variate equation with only limited agreement on how to enumerate all the different elements involved and what amounts to an optimal outcome.

The Gatwick situation perhaps best helps crystalise these issues. Prime Minister Keir Starmer and his Chancellor have strongly argued for the go ahead to be given to Gatwick Airport’s controversial second runway on Economic Development grounds, despite opposition from environmental campaigners and local residents. The Prime Minister linked it directly to the Government’s quest to build new infrastructure that drives economic growth.

“It’s obviously great for businesses, travel, and those people who want to go on holiday because the increased size of the airport means more passengers getting through” he said. “For local people for jobs, it’s really good.”

It seems that ‘behavioural change’ in terms of seeking to deter people from flying at all, is not on the table.

Starmer spoke after Gatwick’s plan to convert its emergency runway for regular routine use was given Planning Inspectorate approval, in an 172 page Development Consent decision letter endorsed by Transport Secretary, Heidi Alexander. It is claimed the plan will create 14,000 jobs and inject up to £1 billion into the economy, but campaigners say that the expansion at Gatwick, and others promised for Heathrow and Luton are incompatible with the government’s net zero targets, a concern also raised by the Labour chair of the Commons Transport Committee.

In a newspaper interview the Prime Minister insisted that it is possible to ‘do both’ – support growth and meet Britain’s climate targets. “You don’t have to sort of say to people nobody can travel in the way they want anymore. I think that would be completely the wrong thing to do. Obviously, as part of the package, you would expect, there are noise conditions to make sure that it doesn’t add significantly to noise for local people. And a condition that public transport must be used for over half the people going to Gatwick.” That condition, however, appears to actually only be a target - and to achieve it will require significant behavioural change

In giving approval to the new runway, the transport secretary has embraced the recommendation of the planning examination for the Development Consent Order, which strongly featured the matter of targets for surface access by sustainable modes rather than by private vehicles. It had been mooted that the airport operator would commit to such targets, and be held to account for achieving them, but at the examination, they pointed out that it would be unrealistic to make the airport responsible for something it could not control. Indeed the alternative modes are obviously a key factor in giving people willingly or unwillingly, the choice to come without a car. That means attractive and reliable public transport — train and bus, and possible suitable cycle provision for both travellers and airport workers.

One ‘stick’ to go with such carrots would be strict parking controls at and around the airport, so that the ease of driving and leaving a car on the acres of long-stay parking around it is modified. Alongside this, coming in a car and simply being dropped off used to be regarded as something that could be done without charge, but now it is widely a paid for facility and no doubt an important income generator for the airport operator, as are the long and short stay parking lots.

The journey to the airport itself cannot in any case be considered as a distinct and isolated decision, as when that journey needs to be made is highly influenced by the airlines and their own charging systems for tickets. A cheap flight at an unattractive time may generate a a decision to drive over and above using public transport, or to use a non-private car mode such as taking a taxi, private hire vehicle or an Uber. How can these trade-offs and the implications for the individual modes be included as part of the equation?

There is an interesting conjunction here between the business and operational planning models of the airport and airlines, which help them optimise their own commercial performance, and what would be modelled by any agency whose objective was a much broader and different one, i.e. to achieve a more sustainable set of travel behaviours and trigger different modal choices.

It is doubtful if such multi-dimensional tools are available to the local transport authorities, planning inspectorate, or other parties interested in the public interest outcome, whether it be climate change and decarbonisation, optimum use of the highway network, or limiting the need for additional road capacity.

An over-riding consideration, is of course, whether the new runway itself is really required- both commercially for the airport operator and in the nation’s overall economic interest as the Prime Minister and Chancellor argue. And related to this, how many additional flights are acceptable, and perhaps the issue of how increased air travel could be accommodated by other changes to the aviation sector’s operational activities from take-offs and landings, slot allocation, and ground movements, to passenger and baggage handling, in which equations the peak flows are a clear determinant of required capacity levels.

The issue is clearly complex, and consequently the idea of driving behavioural change should arguably be approached in a much more sophisticated way than simply by measuring modal shares, which might not necessarily be the right framework for properly thinking these matters through. ‘Progressive’ transport planners have a habit of lighting upon headline figures for modal split, as both objectives and outcomes, and wanting to pronounce them ‘good’ or ‘bad’, when the real issue is much more fine-grained and multi-dimensional.

As often, sound-bite transport policy objectives are easy to express, but harder to demonstrate as being logical and beneficial in all their detail across the wider public policy terrain , not to mention to actually deliver.

In a mixed economy, the elements of transport activity and responsibility range across private and public sectors, and commercial and social objectives. It took decades , and much damage, for the real implications of transport externalities to be fully (or at least generally) recognised - and that was before the ability to measure carbon and climate implications in all their complexity was addressed.

Public policy and regulatory measures, in transport as elsewhere, should properly be rooted in well-understood and generally accepted principles. Unfortunately, there are a range of different perspectives and priorities being routinely brought to bear on the same subject matter. This means that agreement is invariably unlikely on what represents a good way forward. And that’s where more hard-nosed politics and factional standpoints tend to take over the debate.

Peter Stonham is the Editorial Director of TAPAS Network

This article was first published in LTT magazine, LTT923, 2 October 2025.