Normal life has been disrupted in the city
Operators of private buses and taxis in the Indian city of Calcutta say they have called off their strike.
Their action was in protest against a decision by the West Bengal government to implement a ban on commercial vehicles more than 15 years old.
The ban, ordered by Calcutta's high court, was aimed at cutting pollution after studies found high rates of respiratory disease in the city.
Vehicle operators said they would lodge a court appeal against the ban.
The president of the Calcutta Bus Owners Association, Swarnakamal Saha, said he would take the matter to India's Supreme Court.
He said that they would fight the battle legally rather than inconvenience millions of passengers.
The ban will be effective from 1 August - but it has infuriated bus and taxi operators.
They say they would have no hesitation in switching to green fuels or buying new vehicles, but would need loans and easy repayment terms to help them make the move.
Environmentalist Subhas Dutta, who filed the case in the high court that led to the judgement, says that transport owners have had enough time to organise funds and switch to new, green-fuel vehicles.
"This case has been in the court for a long time and the transport associations tried their best to stop an order for scrapping of old vehicles. Now they have no excuse," Mr Dutta said.
As some 60,000 taxis and 10,000 buses went out of circulation in India's third most populous city, the strike had a major impact, correspondents say.
There were huge crowds at metro stations and schools and universities shut down for the day.
The state transport minister Subhas Chakrabarty said that efforts to prevent the strike failed because the transport operators were unreasonable.
The city's ageing vehicles are seen as a major cause of air pollution and responsible for the sharp rise in lung cancer and similar diseases in the city.
Mr Chakrabarty said that nearly 3,000 buses and mini-buses and almost 6,500 taxis will have to go off the roads or convert to green fuel because they were bought more than 15 years ago.
But Swarnakamal Saha said vehicle operators are simply unable to afford the move.
"We understand the environmental concerns, the need to protect our people from pollution. But most of us don't have enough money to buy new taxis and buses on our own and the banks are cautious to lend in a climate of economic downturn," he said.
"This is where we want government support."