Construction of Cycle Superhighway 11 (CS11) will begin next year, Mayor of London Sadiq Khan has announced.

The 2.5-mile cycling route between Swiss Cottage and Portland Place will make it “safer and easier” for cyclists and pedestrians to get around London, Mayor Khan said, and could be complete by late 2018.

The gyratory at Swiss Cottage will be removed from autumn 2017, while Transport for London (TfL) also pledged to change the area’s one-way system as part of its plan to modernise one of London’s “most dangerous and intimidating junctions”.

There will also be a wider segregated cycle track on Avenue Road to accommodate the expected high numbers of users, and changes have been made “that will significantly reduce the amount of traffic moving onto residential streets”.

Though Mayor Khan said he had “worked hard to listen to the concerns raised and taken these into account”, campaigners opposed to CS11 have reacted furiously to the announcement.

Daniel Howard, director of Re-Think CS11, said the plan has been “catastrophically badly designed” and has “condemned thousands of people to years of misery” after attending a meeting with TfL last night.

Re-Think CS11 has launched a petition against the plan which has already gained more than 4,500 signatures.

But Mayor Khan said the scheme is key to improving transport in the capital – and stressed TfL was learning lessons from previous Cycle Superhighway plans as part of his pledge to spend £770million on cycling up to 2021/22.

He said: “CS11 had been left in an absolute mess by the previous administration, with the community divided.

“But we’ve worked hard to listen to the concerns raised and taken these into account, while still delivering significant improvements for pedestrians and cyclists.”

He added: “We will also be working with the Royal Parks to see what further improvements could be made in Regent’s Park to make a real difference to safety for everyone, at all times of the day. Together such improvements will make cycling safer and easier for all Londoners in the area, helping to make cycling a part of their everyday lives.”

Mr Howard, however, said residents had not been listened to – and branded changes to the plan “meaningless tweaks”.

He said: “Despite months of detailed meetings with us and other local stakeholders where we have repeatedly raised your concerns about unacceptable traffic ‘reassignment’ onto residential streets, increased pollution, increased disruption and severe adverse impact on the emergency services, disabled, businesses and road users who rely on motor vehicles, TfL (and Camden Council under the shameful direction of their Councillor Phil Jones – Cabinet Member for Regeneration, Transport & Planning) have condemned thousands of people to years of misery from CS11 construction works and associated impacts.”

Of the “minor” changes, Mr Howard explained that a right turn will be permitted at the bottom of Fitzjohns Avenue/College Crescent into Finchley Road northbound.

He added that a re-introduction of “a banned turn right from Finchley Road into Hilgrove Road (which we pointed out to them will cause traffic to back up all the way along Finchley Road)” was also pledged.