The government is going to pay public transport operators at least £11 billion  extra this year to keep trains, trams and buses running through the pandemic. That is on top of what it would normally have spent on public transport, which was £23.5 billion in 2019–20. These are huge figures.
Some argue this proves public transport is poor value for money, and we should instead invest in roads.
So, what is the public cost of private transport?
Investment in building and maintaining roads is running at around £11 billion/year. That is dwarfed by the ‘external’ (indirect) costs of injuries and damage to property from collisions; impaired health and premature deaths caused by air pollution and inactive lifestyles; and the manifold impacts of carbon emissions and other ecological damage. Totting up just what we are able to value yields a total well in excess of £50 billion/year. 
Then there’s the cost of congestion: lower productivity of logistics and on-site service businesses, and the subjective value of wasted time. By one estimate, that is at least £7 billion/year, or £552 for an average driver in Cambridge.
We cannot build our way out of congestion. Plenty of cities bear the scars of building ever wider roads, flyovers and tunnels, but congestion always returns – typically within two years. Furthermore, a single road scheme, such as the Lower Thames Crossing, can do more damage to human and planetary health than the entire HS2 railway.
Investing in building more road space for people to travel in private cars is just not a viable option. We have to invest in modes of transport that are more space- and energy-efficient, and accessible to everyone, regardless of age, wealth or abilities. Central and local government must do that with the clear aim of enabling people to lead fulfilling lives without owning a car.
It’s up to us to get this message to politicians: we can support short-term, hugely expensive fixes like dualling the A428 and A10, or we can support a sustainable, equitable future around public, shared and active travel. Supporting both is delusory.
 £30.4 million/week or £1.5 billion/year to bus and tram operators in England outside London; £3.5 billion to Transport for London; £3.5 billion to rail operators confirmed, with whole-year costs estimates at £6–12 billion.
 National road building/maintenance: £5.6bn; local road building/maintenance: £5.3bn (source: PESA). Medical & ambulance: £1.8bn; policing: £0.2bn; insurance & damage to property: £6.1bn; lost output (absence from work owing to injury): £4.6bn; subjective value of loss of life or disability: £22.8bn (source: RAS60003). Carbon emissions: £8.1bn (118Mt CO2e @ £69/tCO2e).
This article was first published in the Cambridge Independent on 30 September 2020.