A Sunday in October in São Paulo, Brazil’s biggest city – population: 11 million – and Ezra Teter is setting off on his bike along the Minhocão, literally “the big worm”.

Three and a half kilometres in length, the elevated highway cuts through the city centre joining eastern and western communities. But at weekends it is closed to traffic, turning into a playground for runners, skaters, street artists and strolling couples.

The Minhocão’s closure – on weekday evenings, Saturday afternoons and all day Sundays – has given a semblance of peace and quiet to central São Paulo. Such schemes are helping residents to reclaim streets from motor vehicles, and Teter believes this is just the first step in an ongoing revolution. The athletic-looking English teacher calls himself a “militant cyclist”. Six years ago he came from his hometown of Austin, Texas, by bike to settle here. Since then he has cycled everywhere. Other inhabitants of the city, despairing of the congestion, have done likewise, encouraged by a growing number of cycle tracks. “Things are gradually changing,” he says.

“Minhocão is emblematic of the era when cars were all-powerful. Seeing residents reclaiming it so easily is a powerful experience,” says architect Marcio Kogan. With his friend Athos Comolatti, Kogan has joined the “battle of Minhocão”, the aim being to turn it into a green swath like the converted High Line railway track in New York.

Officially named the Via Elevada Presidente Costa e Silva, the elevated highway opened in 1971, under the military dictatorship when there was no chance for opponents to air their views. It wrecked the historic town centre, which degenerated into an area now commonly known as Cracolândia, where drug addicts gather. At every local election, candidates were asked about their plans for the Minhocão. Ambitious schemes have been floated, but the massive structure is still there.

Fernando Haddad, a member of the ruling Workers’ party (PT), came to power in January 2013, with no special plans for the road. “It should never have existed,” he says simply. Comolatti rose to the bait and now campaigns to make it a city park.

He is not alone. Francisco Machado, who heads the Desmonte Minhocão movement, is calling for what he says is “a scar” on the face of São Paulo to be demolished. The windows of his flat are barely five metres away from the thoroughfare. Worn out by the din and soiled by the pollution, he dreams of getting rid of it and creating a “broad avenue” in its place.

“Every week I have to wash my filthy curtains. But I can’t take my lungs to the dry cleaners,” he says. He thinks it unrealistic to imagine that it might become a park. “Some 70,000 vehicles use Minhocão every day. Where would they go?” he asks.

Facebook Twitter Pinterest The Minhocão on a weekday when it is the main east-west highway across São Paulo, Brazil’s biggest city. Photograph: Antonio Miotto/Corbis

Mayor Haddad doesn’t have the answer, but suggests several radical options. He plans to “de-activate” Minhocão. Despite the fact that people in numbers comparable to the population of Uruguay travel into the city centre from the east every morning, he aims to reduce the amount of space given to cars, lower speed limits, and build more bus and cycle lanes.

So far more than 350km of cycle tracks have been laid out. The number of road accidents has dropped and traffic is more fluid. According to the TomTom ranking of urban congestion, São Paulo is now doing better than Paris. But the response of local residents is lukewarm. A month ago Haddad was assaulted at the official opening of one of his cycle lanes.

“In São Paulo we have the world’s most cosmopolitan residents, but they are also the most parochial,” Haddad complains.

São Paulo’s massive social inequality is typical of the whole of Brazil. Cars are a status symbol. Only the poor use public transport, which is slow and uncomfortable. Residents in Higienópolis, an upmarket neighbourhood, resorted to blows when they tried to stop a Metro station being built. They feared an influx of petty criminals from the suburbs.

São Paulo is an aggressive place, which has developed ‘organically’, in complete chaos,” Kogan explains. With no urban master plan and a hatred for architects during and after the dictatorship, the city displays all the faults of a megalopolis. The population of the city itself is so huge the place is bursting at the seams.

According to Brazil’s Instituto Saúde e Sustentabilidade (Health and Sustainability), fine-particle (PM2.5) pollution in the city stands at an estimated 20 to 25 micrograms per cubic metre of air (more than twice the acceptable limit set by the World Health Organisation). A study by the institute claimed 4,655 people died in São Paulo in 2011 as a result of air pollution.

“São Paulo has a car culture. Public transport is bad, railways and the Metro are inadequate,” says Evangelina Vormittag, who is the organisation's leader.

Clodoaldo Pelissioni, in charge of transport at São Paulo state council, thinks it is just a matter of biding one’s time. Ten projects are under way to upgrade and extend existing Metro lines. It is hoped work will be complete by 2018, but austerity measures now being imposed on the country could delay matters. An increase of just a few cents in the price of a bus ticket, now 3.5 reals ($0.90), sparked demonstrations in 2013, but Pelissioni has no intention of cutting prices.

Ezra Teter cycles on undaunted. He is convinced that São Paulo residents are gradually waking up to the damage done by pollution and that, in time, they will give up their cars. “Whether they’re ready or not, it’s going to happen,” he says.

This article appeared in Guardian Weekly, which incorporates material from Le Monde