I stopped cycling in Paris 10 years ago, when I was clipped by a car door and fell on my head. (Commenters, please fill in own jokes here.) Now I’m about to buy a bike and start again. The boulevard that runs from my home to my office is being equipped with a proper cycle lane, separated from cars. The cross-streets are still crammed with angry drivers running red lights, but a friendly epidemiologist assures me that the health benefits of cycling outweigh the risks.

I’ll be riding straight into a class war. Two rival forms of mobility are coming into conflict: suburban and rural car owners versus unmotorised city dwellers. This class war erupted first in France, where Emmanuel Macron’s plan to raise fuel taxes by 4 cents a litre prompted the uprising by the mostly provincial gilets jaunes, whose symbol is the yellow vest that all French motorists must carry. Now the conflict is spreading and will eventually reach even the US and UK, currently still distracted by the politics of the past. The new political battlefield is the road.

Famously, today’s big political divide is between liberal cities and their populist hinterlands. That divide will grow as cities push out polluting and space-eating cars. Paris’s mayor Anne Hidalgo has already infuriated suburban commuters by closing the city-centre highway. By next year, she wants 15 per cent of all Parisian journeys to be made by bike, up from 4 per cent now. Around town, bike lanes are replacing car lanes.