The government estimates that by 2050 traffic levels in England and Wales could rise by as much as 51% compared with 2015.
Even under the most conservative of those scenarios modeled traffic goes up by 17%.
According to the Department for Transport’s Road Traffic Forecasts 2018, van traffic is expected to grow fastest of all, anywhere between 23% and 108%.
The growth is accounted for by a growing population – hence more trips overall – and reductions in vehicle running costs.
Rising traffic is matched by a decline in average speeds.
The forecasts also suggest that by 2050 despite the rise in traffic, tailpipe CO2 emissions from road vehicles will reduce by anywhere between 17% and 76%.
One of the greatest uncertainties surrounds how autonomous and connected vehicles will change travel demand and vehicle utility.
Steve Gooding, director of the RAC Foundation, said: “The Government recognises that the big unknown is the impact of driverless cars. In the future we might all still want to travel as much as today but the overall number of cars licensed could fall as each one is shared more and does a higher number of trips.
“At the moment the average car sits parked 96% of the time taking up kerb and drive space.”