One of Cardiff's busiest streets is being closed on Friday and Saturday nights amid safety concerns over people spilling out from pubs and clubs.
Motorists have already been stopped from using St Mary Street
Greyfriars Road will close to traffic from 2000 GMT to 0400 GMT on both weekend nights for the next 18 months.
Motorists have already been stopped from using the nearby St Mary Street as an experiment this summer.
Police said the bus lane running along the road would be turned into a marshalled taxi rank.
South Wales Police Ch Insp Steve Furnham said officers would "fully support the taxi rank on Greyfriars Road after 1130pm".
"We encourage everyone to use the taxi rank as a safe and secure way of getting home after a night out".
Cardiff council announced the temporary closures were a joint operation with the force and would continue until June 2009.
Greyfriars Road was closed westbound , from the New Theatre towards the Hilton Hotel, from 2000 GMT on Friday, with buses using the Boulevard de Nantes and Kingsway into the city centre.
Taxis and busies were allowed to travel eastbound until the last bus which was at approximately 2330 GMT, and from then on the road was completely closed to general traffic.
The bus lane was being used as a taxi rank with a taxi marshal from South Wales Police to supervise people getting in and out of taxis.
Cardiff Bus stopped running services westbound along Greyfriars Road in September because of safety concerns about passengers and members of the public using the road during the busy weekend period.
The bus company said the introduction of the smoking ban in enclosed public places had forced smokers onto the paved areas of the road.