Council chiefs were joined by Sadiq Khan at Highbury Corner to officially unveil the new junction and public space.
The mayor of London was on hand to cut the ribbon this morning following the completion of the long-awaited overhaul of the dangerous and intimidating roundabout.
Work began in April last year to make the area safer for cyclists and pedestrians, and it now includes segregated cycle lanes, green space on what was the roundabout, a new station forecourt and wider pedestrian crossings. It has been criticised by some for causing gridlock, though council chiefs put it down to teething problems.
Town hall transport chief Cllr Claudia Webbe said: "We campaigned hard to change a dangerous and outdated junction into a much more welcoming and pleasant place for people."
Mr Khan said: "With thousands of people dying prematurely every year as a result of our dirty air and our inactivity crisis, it is essential other boroughs follow Islington's lead in getting more Londoners walking and cycling everyday."
London Cycling Campaign campaigner Simon Munk praised the mayor and council for taking action. He said: "It is vital we press ahead in civilising the most dangerous junctions in London, on TfL and borough roads, to reduce road danger - the single biggest barrier to more people, and a wider range of people, cycling."
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