The government should also introduce more measures to help drivers switch to walking, cycling and public transport, according to the Green Alliance.
It says switching to electric vehicles will cut carbon emissions, but reducing traffic is also needed to make sure the UK hits its 2030 climate target.
The Green Alliance report calls for greater national investment in public transport over the next decade, as well as more support for local authorities to improve facilities for active travel and to make neighbourhoods more walkable.
Helena Bennett, senior policy adviser at Green Alliance, said: “Switching to electric vehicles is the top priority for cutting emissions from cars, but it can’t be the only tool used to make transport greener. Better and more affordable public transport, safe cycle routes and walkable places must be a centrepiece of the government’s transport strategy.”
The report highlights the economic benefits of traffic reduction. Shifting just 1.7% of car journeys to active travel would provide the UK with up to £2.5 billion per year in health benefits. Reducing congestion would also provide an economic boost, as the cost of congestion was estimated to be almost £8 billion per year.
Data published by the Inrix Global Traffic Scorecard showed that UK fleets and drivers lost 73 hours this year to congestion. The figure is up from 37 hours in 2020, but down from 115 in 2019.
Green Alliance’s study analysed fast, medium, and slow electric vehicle sales trajectories in the period up to the UK’s 2030 ban on the sale of new petrol and diesel cars. The fast scenario is based on the Climate Change Committee’s recommended rate of uptake to meet climate targets, the medium trajectory was calculated by Green Alliance and aligns with government’s prediction of average sales rates, and the slow trajectory is the Department for Transport’s own worst case scenario, of only 50% of vehicles sold in 2030 being purely electric.
The study found that, even under the medium sales trajectory, which the government thinks is most likely, the average annual mileage per car would have to fall by around 1,700 miles if emissions targets are to be met. Under the slow sales trajectory, the annual average mileage per car would need to be cut by almost 30%, or 2,300 miles a year fewer, to keep emissions on track.
The Green Alliance recommends the Government takes decisive action now to set ambitious ZEV mandate targets but also take steps to manage future traffic levels.