Drivers in Swansea are claiming the new Kingsway road layout is too narrow.
Work is currently under way to transform it into a two-lane, two-way route but with diversions and barriers in addition to the bus stops.
Swansea Council has said the aim is to make it a more pedestrian-friendly space, and pointed out that a 20mph limit is in force.
At the moment there are two lanes along the Kingsway both travelling the same direction, meaning cars coming from Orchard Street and College Street travel side by side.
But drivers are claiming that the lanes are too narrow and have raised concerns for buses also using the city centre route.
Daniel Thomas said: "As a current bus driver just dealing with the cars can be a challenge at times."
Ciah Llewellyn added: "When travelling down the Kingsway with a larger vehicle travelling parallel with you you can't see pedestrians crossing on the zebra crossing.
"You just have to guess that when the other car/bus slows it's for good reason. This is a safety hazard."
Adrian Lewis said: "Was behind a bin lorry doing its rounds, there's not much room for another vehicle of similar size."
And Louise Treasure said: "There is no way that this is going to work. Two way traffic when it's not wide enough for two cars as it is going the one way. That's without the buses."
Kingsway has changed a lot:
The pavement now appears much wider, with flower beds planted in front of some shops, as the council aims to create a more pedestrian friendly environment.
Drivers are being advised to stick to the speed limit of 20mph along the Kingsway, which will remain in place once the redevelopment work has finished.
A Swansea Council spokesman said: "The new Kingsway layout has been designed to create a more pedestrian friendly space along the route and forms part of our wider regeneration of the city centre.
"The ongoing works include the reintroduction of two way traffic along the route with one lane in each direction. The remaining space is being transformed into open space for families to spend time in a safe environment.
"Introducing two way traffic on surrounding roads will also assist the council in encouraging motorists to use alternative routes to travel through the city centre, easing congestion and making roads safer.
"While ongoing works are being completed motorists should drive responsibly, keeping to the advertised 20mph limit. This limit will also be in place when the redevelopment is completed."
