The window of opportunity to take action to mitigate against severe climate change is right now, it won’t last.

This isn’t a remote problem that someone else must fix. It’s one we all must embrace. This need for action should guide much of what we do in transport, where emissions are higher than for other sectors. That is the “upstream problem” that should drive every action “downstream” for surface, air and shipping transport. Targets and action should be led by the science. As the saying goes, “science without policy is science, but policy without science is gambling”. To the Scottish Government’s credit the target to reduce car kilometres travelled by 20 per cent by 2030 is based on what we must achieve by 2030.

Here and now our expectations for travel are a problem, or to be more precise the travel behaviours and expectations of the wealthier segments in society are. The wealthiest drive on average 2.5 times more than the poorest and hence produce higher tailpipe emissions. Moreover, the current regressive taxation regimes result in the poorest drivers paying over a quarter of their disposable household income on motor vehicles compared with 8% for the wealthiest households. This matters.

We cannot transition to low and no carbon transport, even just considering urban areas, without supporting those on low incomes. The biggest emissions reductions contribution have to come from the biggest emitters. In the world of road transport researchers speak of “latent” and “suppressed demand” for active travel. There is a store of evidence that if the environment was safer (same low risk of injury as for car occupants in urban areas) many more people would choose to walk, cycle, and use public transport for those under five-mile urban trips (suppressed demand). Such change would have ripple effects to stimulate “latent demand” – where services that don’t yet exist or facilities that if put in – make environments more attractive and stimulate sustainable transport use.

Humans are, however, not keen on changing their travel behaviour. In recent decades, we have tried to use voluntary approaches, with hopes of technological fixes being enough, including electric cars. While we do need technological advances to bring down overall transport energy demand we also absolutely need substantial lifestyle changes too.

So, removing multiple barriers to behaviour change is key and one of the top ones is loss aversion. This includes the comfort of my own space, not beholden to timetables, and the status that certain car brands are perceived to convey to some. We will need help here through other channels. Who are our change facilitators? Who influences us consciously and unconsciously? Some of these are surprisingly close to hand – neighbours, friends, as well as celebrity endorsements – not for car brands – but for bus, train, bikes, walking and car-sharing.

But do Scots really perceive the threat as real and urgent? Faced with an invisible virus, we have achieved major changes – including how we travel –over the past two years. Politicians were understandably nervous of that too many wouldn’t obey orders and new social norms. Yet, they did obey. So, part of the communications work, and not just from Government, must be demonstrating the tangible threat but that working together, we can reduce our transport carbon enough while retaining quality of life.

An aide in planning the transport sector energy transition is to consider enabling choice, helping people choose pro-environment travel modes they would be attracted to if it were not for various physical, fiscal, or other barriers. We can think of nudges to travel behaviour change like going up rungs of a ladder. We can move up one rung simply by offering information on the basis that most of us have imperfect knowledge of the range of travel options available. That is, however, very unlikely to achieve much change at all.

We have to go up two rungs or more. This can involve changes which offer a pro-environment choice as the default option and which is incentivised in several ways. The incentivisation may include significant time savings by travelling by bus, with further incentivises, such as cheaper entry to events or shop discounts. Any disincentivises to car use added on top, such as reallocating one of the two lanes of dual carriageways to buses and bicycles, makes the sustainable travel options more attractive.


The UK has the most expensive public transport in Europe which incentivises people to drive not least through up-front investment in car ownership which stimulates use. That “locked in” barrier to other modes has to become the exception, as has happened far more on continental Europe with car-clubs and sharing schemes which then removes the substantial upfront ownership costs.

Payment by use would also be fairer. In Scotland we have the welcome move to free bus travel for the under 22s since January 31st. If we then provide more dedicated road space for buses as a positive intervention and increase car parking charges the price signal will more likely enable pro-environment choices. For example, those aged 60 plus with free bus travel, can now take their grandchildren out using buses rather than driving a car.

Think too about central London, most people don’t drive or limit their driving because there is a weekday 7am to 6pm and weekend 12.00 to 6pm charge for entry. If, however, you have an ultra-low fuel vehicle you are exempt, so that’s a price disincentive through the charge (with some exceptions) plus some incentives. That’s not a great example as it’s still largely regressive, and residents in the zone get a 90% discount.

But the other factor is that the public transport options are very obvious, prices are capped to make them more affordable and the system with contactless payments is relatively easy to use. That’s up a couple of rungs on the ladder – guided choice through incentives. Here, bus use is a social norm – you use it regularly, your neighbours do too, and it’s become an engrained habit for the majority.


Enabling choice forms part of a ratcheting up which may need to include restricting choice in order achieve the carbon reductions needed, particularly among those who travel most. This series of steps is taken from the Nuffield Ladder of Interventions.

It is a method of thinking about the acceptability and justification of different public health policies. It also has to be multi-layered, in that we cannot really on just a few incentivisation “carrots”. Incentives must be widespread, systematic and obvious. In a 2019 study of how to get more people walking and cycling the evidence for positive impact was greatest for whole town and city-wide interventions. This means multi-faceted incentivisation and revolved around investment in the physical infrastructure.

The messaging needs to be targeted to the numerous travel segments – from teenagers, the 20-30 year first car owners, to young mothers, elders and so on. All of this requires a huge effort, galvanised in that we are “in it for good”. A coda is that all of the above may seem wishful thinking. Yet if we look back through the history of humans settlements the car age is just a blip in time, a likely cul-de-sac, and that we can reshape or towns and cities now to be healthier and more resilient in mitigating against severe climate challenge.

Dr Adrian Davis: Transport and health specialist at Edinburgh Napier University