A road layout expert has warned that four plant pots used to slow traffic could result in increased response times for the emergency services.

The controversial plant pots were installed along Viaduct Road in Brighton to tackle a speeding problem as only 20% of motorists obey the 20mph speed limit.

But David Wickens, a retired traffic manager and former head of engineering and project management for Croydon Council, has warned the width restrictions could cause problems for ambulances and fire engines.

However, the council dismissed the claim saying: “No local emergency services have raised this as an issue.”

East Sussex Fire and Rescue Service (ESFRS) said it was “monitoring” the situation but has so far raised “no such concerns”.

Mr Wickens, 57, of Burgess Hill, said the pots would restrict traffic flow and delay emergency services and he added that the council had in some ways created its own problem by imposing the speed limit on the road.

He said: “The proximity of the fire station and the fact that it is a preferred route for ambulances means that any width restriction could increase journey times.

“I had to pull over to assist an ambulance that was struggling to get through, not helped by the planters.”

Mr Wickens said he often travels the route on his motorcycle and fears the pots could be lethal to motorcyclists.

He recommended the speeding situation could be resolved with an increase of the limit to 30mph.

Speed cameras, speed cushions and limited residents’ parking on the road were also possible solutions to slow cars down, he said.

Mr Wickens also offered to act as an “expert witness” for any claimants against the council as a result of the obstructions.

A spokesman for Brighton and Hove City Council said: “No local emergency services have raised this as an issue.

“There is ample space for emergency vehicles to get through with drivers’ usual co-operation. There remains a great deal more space there than on many other city roads.”

A spokeswoman for ESFRS said: “We would like to remind motorists that they should pull over as soon as it is safe to do so, to allow emergency vehicles such as fire engines to pass.

“In heavy traffic it is advisable to leave space between your vehicle and the one in front to be able to do this quickly.”