Motorists in Southampton have been spotted driving through a stretch of a city centre road on the day it opened as a bus zone - sparking anger over signs that 'blend in' with the street.

A section of Portland Terrace – between Spa Road and Castle Way Car Park – closed to all traffic other than buses, cyclists and taxis on Monday.

But drivers of private cars were seen driving through the road at lunchtime despite signs warning of the new restriction.

Warning notices are set to be issued by drivers flouting the restriction before any fines are issued in future.

Several nearby bus passengers told the Echo that Southampton City Council should use flashing signs to let drivers know of the change.

Daily Echo: John Sherman, 82John Sherman, 82 (Image: Newsquest)

John Sherman 82, from Bursledon, said: “People driving through this road are focused on the car in front of them and will often not read the post signs or on the floor.

“The signs just blend in with all other signs on the street and people don’t pick it up.

“There should be a flashing light saying no cars past this point. There just needs to be better signage for drivers to see.”

Daily Echo: Cars driving on a section of Portland Terrace which closed to all traffic but buses, taxis and cyclistsCars driving on a section of Portland Terrace which closed to all traffic but buses, taxis and cyclists (Image: Newsquest)

Passenger Irene Duff, 82, from Lordswood, said: “A flashing light would definitely be better.

"Otherwise, drivers will just drive here on not take any notice of the restriction.”

One bus driver told the Echo: “It's still going on and will do for a while, the council could have put in extra temporary signage.

"But motorists would probably ignore it. I’m surprised the council haven't got staff out stopping them.”

Daily Echo: Cars driving on a section of Portland Terrace which closed to all traffic but buses, taxis and cyclistsCars driving on a section of Portland Terrace which closed to all traffic but buses, taxis and cyclists (Image: Newsquest)

The bus, taxi and cycle-only zone attracted mixed views from city residents.

The council says this restriction will improve bus journey times to the new Albion Place bus hub, which is planned for construction early next year. It's hoped this change will reduce journey times across the city by up to 10 minutes.

A spokesperson for Southampton City Council said: "The council will be evaluating and monitoring the scheme by a range of methods including a review of signage and also using CCTV to monitor driver behaviour.

"If there is a high level of contraventions, we will have the option to enforce the bus-only restriction.

"If cameras are used for this purpose, it will be in line with government guidance and council policy, which amongst other requirements will mean the issuing of warning notices for a period of time prior to enforcement starting.

"We have installed warning signs at all approaches to the bus/taxi/cycle-only section of Portland Terrace so that drivers can plan their journeys accordingly."