The new Office of National Statistics report on carbon emissions and road transport should be a wake-up call. Despite the pressing need to cut emissions, greenhouse gases from road transport have increased by 6 per cent since 1990.

For decades the main solution to the UK’s congested roads has been to build more. The UK government spends over £10bn on our roads every year, or about 1.2 per cent of all government spending. By any standard that’s a lot of money. And while it has long been obvious that the environmental impact is unsustainable, recent research has weakened the case for road building.

So why are we still building new roads and is it time to stop?

What’s the benefit of more road building?

Building roads is supposed to cut congestion and speed up journeys.

But a review by Highways England published earlier this year found that, overall, dozens of roads were more congested as a result of road building. A 2017 analysis by Campaign for Rural England (CPRE) of 25 road building projects found only five had evidence of any impact.

In the long-term, new road space encourages more journeys by car until the extra capacity is clogged up once again. In fact, the same CPRE review found that road building commonly created congestion on nearby roads, leading to calls for even more road building. 

UK roads have a massive carbon impact

Around 30 per cent of the UK’s carbon emissions come from vehicles on our roads, including 18 per cent just from cars. Road transport emissions have increased in the last 20-years despite improvements in technology – largely because people are driving more.

The mooted cut to fuel duty would only encourage even more car use at a time when we need as many journeys as possible to be made on foot, bike or by public transport.

The UN Intergovernmental Panel on Climate Change says we have until 2030 to halt climate change. Electric vehicles will help, but not soon enough. The UK government knows this, which is why it has only committed to end the sale of fossil-fuel vehicles a decade later in 2040. The UK Committee on Climate Change has said this will not contribute to keeping global warming to 1.5 degrees.

Invest in cycling and walking infrastructure and a zero-carbon future

There will be billions of pounds available if we stop building new roads. Over 10 years, we could fix the £11.6bn backlog of road maintenance and still have about 90 per cent of the bloated road building budget left each year.

The government could use this money to focus on building safe walking and cycling infrastructure for children to travel to school. In our busy towns and cities, tackling the school run and taking those car trips off the road could have a much bigger impact on congestion.

We should be building protected cycle routes on arterial routes to make cycling a safe and convenient transport mode for millions of people to get to work, the shops and most everyday journeys.

Infrastructure for walking and cycling is a fraction of the cost of roads, but it’s what you get back that matters. A Department for Transport report boasts of a £4 return on investment for every £1 spent on certain major road schemes, but the average return on investment for cycling is £13 for every £1 spent.

We should also put more money into clean, affordable public transport. We need greater investment in low-carbon bus fleets and bus priority infrastructure to make bus travel fast, convenient and green. Continuing the electrification of the railways would also permit faster journeys with lower carbon emissions.

What next?

The severity of the climate emergency means we need system change.

Things might be starting to change in Scotland, where a new National Transport Strategy does away with promoting faster journey times in favour of journey reliability, and declares that transport must contribute to delivering net-zero carbon emissions. The logical conclusion is that building more roads is incompatible.

Separately, an independent review of air quality policy commissioned by the Scottish Government has concluded that national road investment should end in five years and spending on walking and cycling should double to around £30 per head.

The mantra of road building is being challenged by the evidence. It’s time politicians recognised that new roads come at a cost we can no longer afford.

Alex Quayle is senior policy officer at Sustrans.