It's still lights out at the Dome Roundabout after unforeseen problems with cabling to the traffic signals have caused weeks of delays.

Hundreds of motorists using the Dome said they have experienced journey times up to 20 minutes shorter since the traffic signals were temporarily switched off to accommodate roadworks at the roundabout in February.

The county council's work schedule was to have the lights back on by March 30, but now the authority is not sure when the signals will be up and running.

Rob Smith, deputy director of environment, said only the traffic light part of the work had been delayed.

He said: "All civil engineering works at the Dome Roundabout are now complete but, due to an unforeseen issue with cabling, completion of the traffic signalling element has been delayed.

"The footpaths will be re-opened and surplus traffic management will be removed from the site but the temporary signalised pedestrian crossings will remain in operation for the present."

The works at the Dome included widening the pavement around the roundabout to accommodate pedestrians and cyclists, and changing the traffic lights to include a phase for cyclists.

Hertfordshire County Council was to install a new type of software in the traffic lights in a bid to help cut down on congestion from the Dome.

The lights were to be fitted with a "multi-node SCOOT", which would adjust the timings of the signals using real-time data on surrounding traffic queue lengths, cyclists and pedestrians.

But many motorists and the town's top politicians thought the software was a poor solution and have campaigned to have the traffic lights removed permanently.

One petition has been signed by more than 250 residents who agree traffic has been reduced since the traffic lights have been switched off.

Another petition, started by the Watford Liberal Democrats, has more than 100 signatures calling on Herts County Council to investigate turning off the traffic lights at the Dome roundabout, while ensuring that pedestrians and cyclists can cross safely.

However, the county council responded to the petitions by saying pedestrian safety concerns outweighed the benefits of "slightly improved" traffic flow through the town.

The authority only committed to monitoring the situation once the lights were back in place.