Works to overhaul Old Street roundabout have angered motorists due to “chock-a-block traffic” – but transport bosses have urged the public to sit tight while the vital project is finished and finessed.

Transport for London (Tfl), Hackney Council and Islington Council are collaborating on a colossal scheme to pedestrianise part of the deadly Old Street junction, with work set for completion next year. Traffic has already become two-way and a large public space will eventually be created in the middle of the old roundabout - once planners and designers can agree on what it should actually contain.

Transport chiefs agree the "priority is to keep pedestrians and cyclists protected" - and short-term disruption is seen as a worthwhile sacrifice for safer streets.

"It was always going to be havoc," said Cllr Phil Graham, a Labour councillor on the Islington side of the border. "I think the timings on the lights are all wrong."

His fellow Bunhill ward councillor Troy Gallagher told the Gazette: "The revamp and development is much needed as it has been a hazardous junction and one of the worst for cyclists and pedestrians.

"But I do wonder if TfL have thought this through properly and I'm not entirely sure they have listened to residents' concerns on term of what should be done to reduce accidents around there.

"It's been absolutely chock-a-block around here. It took one resident 45 minutes to go from Central Street to Old Street - it's a disgrace."

He claims to have received 56 calls in a day from angry constituents complaining about the traffic and delays to their journeys.

Cllr Gallagher said fumes are a health hazard, and that, during the first few days after works started, drivers were "sliding into each other" because they hadn't realised they were going "the wrong way". He claims there weren't enough signs advertising the work or staff at hand to help with the "fluidity" of the traffic.

TfL changed the road layout of Silicon Roundabout - where Old Street meets City Road - in May, opening it to two-way traffic (meaning it no longer really deserves the name). It's closed the south-eastern junction until November while a new entrance and subway is built in Cowper Street and a 24-inch water pump is diverted. Two-way traffic is now open on the rest of the lethal junction, where cyclist Sarah Doone lost a leg after being run over by a cement truck in August.

Nick Fairholme, TfL's director of project and programme delivery, said: "We'd like to thank local residents and businesses for their patience while we transform the dangerous Old Street roundabout into a space where people can walk, cycle and travel safely. The switch to two-way traffic has been an important milestone for the scheme and some road closures and changes to travel have been required for work to progress safely. Our teams have been closely monitoring the area since the switch was implemented. We have adjusted the traffic light timings to ensure traffic flows through the area effectively. We have also altered signage and road markings to make the routes through the junction clearer for all road users, especially cyclists.

"I'd like to encourage everybody in the area to take extra care as people get used to the new road layout, and we'll continue to work in partnership with Islington and Hackney Councils to make sure disruption is kept to a minimum as the transformation of Old Street continues."

One woman acutely aware of the argument from both sides is Cllr Claudia Webbe - not only is she Islington's environment and transport chief, she's also a Bunhill ward councillor.

"At the end of the day, while works are ongoing, there will be a little impact to people who are driving," she said. "It's not the work that causes the pollution - it's the vehicles.

"And the level of disruption is difficult but necessary in order to achieve the long-term goal. We are working to keep disruption to a minimum but the resultant outcome will mean deaths and serious injuries will have a better chance of getting down to zero.

"I can't live with continuous deaths of cyclists and pedestrians at Old Street. It's one of the most dangerous gyratories in London."

London-wide Assembly Member and Green Party transport spokesperson Caroline Russell told the Gazette: "It's still a building site and I think what's important is that they properly protect people walking and cycling through the area.

"From that perspective, there is some work they've got to do to provide physical, separated lanes."