More than 1,000 people in the West Midlands have agreed to give up their car for the day as part of an international environmental campaign.
The region's public transport executive Centro offered commuters a free travel pass for Thursday's 'In Town Without My Car' Day, if they pledged to travel by bus, train or tram.
A total of 1,350 motorists in the region have agreed to take part, by signing up to the pledge on Centro's website - www.centro.org.uk.. They have each been sent a one-day Centrocard.
Councillor Gary Clarke, chairman of the West Midlands Passenger Transport Authority, which sets policy for Centro, said: "This shows that as the public transport on offer in the West Midlands continues to improve we can all help to cut congestion."
Coun Clarke (Con Walsall Streetly) said that if a reasonable proportion of those taking part in the car-free day continued to use public transport, it would make a big difference.
Motorists are already outnumbered during the Birmingham rush hour by commuters on buses, trains and trams.
The scheme is part of European Mobility Week, which began last Friday and focuses on clever commuting and offering people travel choices.
Coun Clarke said: "We are not anti-car. Our aim is for public transport to be a viable and cost effective alternative for motoring, especially for the daily commute. That way everyone benefits from reduced congestion."
Rachel Hooper, regional officer for TravelWise, the organisation co-ordinating the event, said: "This campaign day is an ideal opportunity for anyone who wants to do their bit to cut congestion and help the environment - and if they are persuaded to give up their car on a regular basis that would be even better."
Recent statistics from the Department for Transport showed vehicles travelled 3,799 million miles in Birmingham last year, an increase of five per cent compared with 1997.
One of Centro's most successful congestion-busting schemes, the park and ride facilities at rail stations and Metro stops, was found to save West Midlands commuters about £10 million a year in motoring costs.