Drivers will not be charged for entering Birmingham's new Clean Air Zone for the first two weeks, the city council has announced.
The scheme, covering the city centre and targeting high-polluting vehicles, was launched on Tuesday morning.
Some motorists reported problems as they tried to pay in advance for their journeys when the council announced its decision to delay seeking payment.
Councillor Waseem Zaffar said the delay would give drivers "time to adjust".
"We always want to give communities that extra time to be able to adjust to such a difficult and challenging project that this Clean Air Zone clearly is," the cabinet member for transport and environment said.
"So for the next two weeks we won't be seeking any payment or enforcement of those payments either."
Mr Zaffar added there were hundreds of people in the city who could still benefit from grants and exemptions available and urged them to apply.
"We're not interested in taking their money, we want green compliant vehicles coming into our city centre," he said.
The decision will mean high-polluting cars, which face a daily fee of £8 to travel into the centre of the city, and coaches and lorries, which will be charged £50, will not be required to pay for journeys before 14 June.
For four weeks after that, drivers will be offered the chance to pay just the daily clean air zone charge rather than a £120 fine if they fail to pay within six days.
A government website allows motorists to check if their vehicles will be affected by the new rules.
All roads inside the A4540 Middleway ring road fall into the clean air zone, but the circular route itself is not included.
The delayed scheme has divided the city, with some criticising the timing of it while businesses attempt to recover from the coronavirus pandemic.
However, the local authority said air pollution contributed to 900 premature deaths a year in the city and it faced a £60m fine if it failed to implement the zone.
Source: BBC