Cars driving along Viaduct Road after a controversial trial involving plant pot chicanes are travelling about 20mph slower than before.
The trial followed a drive by the London Road Local Action Team to improve the feel of the residential road, where 80% of drivers exceed the speed limit.
And in the first week, average speeds have dropped from being in the early 40mphs to 23.5mph – which is still above the 20mph limit.
The scheme has drawn criticism from motorists who say it is only a matter of time before they cause an accident.
But the council says the planters are safe if motorists stick to the speed limit. It also says although the pots are adequately lit according to guidance, it will be adding further traffic signs to each one.
The council’s road safety team manager Martin Heath said today: “We are closely monitoring the effectiveness of the scheme along with any feedback from residents and other road users.
“These obstructions will not present a problem to compliant motorists travelling at reasonable speeds (20mph speed limit).
“Average off-peak speeds pre-planters was in early 40mphs. During Week one this has reduced to 23.54mph (highest speed recorded 56mph). Further measurements will be taken in week two.”