Ring, ring! It’s rush hour on Paris’ Sébastopol Boulevard, and the congestion is severe – not just gas-guzzling, pollution-spewing, horn-honking snarls but also quieter and greener bottlenecks of cyclists jockeying for space.

Until four years ago, motorists largely had the Paris thoroughfare to themselves. Now, its bike-lane jams speak to a cycling revolution that is reshaping the capital of France – long a country of car-lovers, home to Renault, Citroen, and Peugeot.

This revolution, like others, is also proving choppy. A nearly decade-long drive by Socialist Mayor Anne Hidalgo to turn Paris from a city hostile for cyclists – except those racing the Tour de France – into one where they venture more safely and freely has become so transformative that bikes are steadily muscling aside motor vehicles and increasingly getting in each other’s way. And more bike lanes are coming for next year’s Paris Olympics – part of an effort to halve the event’s carbon footprint.