Visitors and residents alike can now glide for miles along the river banks on a bike, protected from the cars by granite separators, or all the way across the city, from Concorde to Bastille, beating the gridlocked traffic. Ms. Hidalgo is aiming for more than 600 miles of bike lanes by next year, up from around 400 when she started.

As monotonous green-gray metal separators, shielding the projects, have sprouted across Paris, the inconveniences have been accompanied by an angry chorus of groans from hapless motorists.

The environmental results are ambiguous at best. There were around five days with elevated ozone levels, for instance, in 2014, the year Ms. Hidalgo took over; in 2018 there were from 15 to 22, depending on which part of the city you were in.

“There are fewer cars, but there is more congestion, and that can affect pollution levels,” said Paul Lecroart, an urban planning expert at the Paris regional planning agency.

But the fights the Spanish-born mayor has already taken on and won demonstrate that she has no intention of backing down.

“There’s been a very violent reaction at times,” Ms. Hidalgo said, smiling slightly in an interview in her cavernous office at the grandiose Hôtel de Ville, the City Hall.

“Part of it has to do with being a woman,’’ said Ms. Hidalgo, the daughter of working-class immigrants from Spain. ‘‘And being a woman that wants to reduce the number of cars meant that I upset lots of men. Two-thirds of public transport users are women.”