Brighton and Hove city centre 20mph scheme starts
A 20mph speed limit for most of Brighton and Hove has come into force despite opposition from taxi drivers.
The ruling Green Party said the limit will make the roads safer for pedestrians and cyclists.
However, it has been criticised by many taxi drivers over fears they will do fewer jobs and may be victims of violence from frustrated customers.
And most of city's speed cameras will not be able to detect speeds lower than 30mph.
Ian Davey, who is the council's transport committee chairman, said: "What we see at the moment is a lot of acceleration and deceleration.
"A lot of people trying to get up to 30mph just to slow down again at the next set or traffic lights.
He added: "Evidence elsewhere shows that reducing speed limits has very minimal impact upon journey times [for taxis]."
The new 20mph limit covers most residential and shopping streets in the city centre, with major roads and routes that take traffic out of the city continuing with the 30mph limits.
Jon Smith, a taxi driver and a GMB union representative, had previously said: "Taxi drivers in general will be disadvantaged in the length of time it's going to take them to complete the jobs and get back into the city centre to take the next fare."