To allow new four-car trains to run on the London Overground network, the North London Line between and was closed between February and May 2010 while a new signalling system was installed and 30 platforms were extended. During this closure, the Highbury & Islington station ticket hall was extended and step-free access installed on all of the London Overground platforms. The North London Line reopened on 1 June 2010; however, the East London Line platforms did not open until March 2011, whilst the Western Curve was reinstated, linking the station to Dalston Junction and the rest of the East London Line.