Traffic was gridlocked at the Bridgehouses Roundabout that connects Derek Dooley Way to Corporation Street in Kelham Island as about 100 members of Extinction Rebellion held banners across the carriageway for five minute intervals between 8am and 9am.
The move sparked fury among some motorists and police officers had to intervene as a yellow car and later a moped crept forward towards protesters.
Members of Extinction Rebellion Sheffield said blocking the road was necessary in order to make people stand up and take climate change seriously.
They specifically want Sheffield City Council to reverse a decision to widen the Inner Ring Road, which they claim will bring more traffic into the city centre.
Protest co-ordinator Dr Bing Jones, aged 67, from Nether Green, described the climate emergency as a ‘crisis’ happening now but criticised the council for a lack of action.
He added: “They are speaking the right speak, they have commissioned a large report which tells them they have to reduce emissions by 14 per cent year-on-year until 2038 but they are still widening the road which will increase traffic substantially into the centre of Sheffield, which is already massively polluted.”
Dr Jones apologised to motorists for blocking the road but added ‘our methods get us into the media’, and added it was important to maximise coverage of the issue.
The protesters briefly parted to let an ambulance through. Among the frustrated honking of horns and revving of engines, one motorist spoke out in support of the protest.
Rebecca Dowling, aged 25, of Doncaster, who was on her way to work, said: “It is a small delay to motorists to make a bigger point. People should have patience and take climate change seriously.”
The protest comes as a £4.6 million scheme to reduce congestion by widening the Inner Ring Road continues. Extinction Rebellion has written to the council demanding a halt to the scheme.
Sheffield City Council went ahead with its plan to widen Derek Dooley Way between Corporation Street and Saville Street despite concerns from dozens of residents about pollution and traffic.
The authority said that widening the road will improve traffic flow which is better for the environment.
Councillor Mark Jones, cabinet member for environment at Sheffield City Council, said he wants to work with protesters to tackle climate change and is confident of ‘achieving a zero carbon economy by 2030.’
He added highlighted how the authority has launched the clean air zone consultation, is trialling green bin lorries and making buses more eco-friendly.
Coun Jones said: “We’re looking at how we can make our city move better. Where possible that may be through no car journeys at all.
“But when a journey is needed we must make sure it is done so efficiently and effectively, impacting on our environment as lightly as possible. We need to put in measures that make mass transport more attractive such as reducing bus journey times. This will be difficult to achieve with our current transport infrastructure.
“Transport corridors must work better to create a more pleasant city. One that supports walking, cycling and access for public transport.
“In the short-term, we anticipate the road widening will improve local air quality and enable us to meet the ambitious targets we have set ourselves. Cycling groups have also been supportive of these changes.”