Redecking the Hogarth Flyover, London

Hogarth Flyover is one of west London’s most notorious flyovers, carrying 10 500 vehicles over Hogarth Roundabout every day. The 250 m long, single-lane structure was built in 1971 as a temporary measure to reduce traffic congestion at the roundabout, with an estimated design life of around 5 years – and is still in use today after nearly 50 years. Following a detailed review and structural assessment by Conway Aecom, the structure was deemed to be in a seriously poor condition. A substandard bridge management system was instigated, followed by an accelerated scheme to demolish and reconstruct the flyover’s concrete deck. To meet the 6-week closure window imposed by Transport for London, repairs were made by clamping new concrete deck panels to the existing steel work supports, which were also repaired. The restorations also coincided with the summer school holidays, minimising the disruption to traffic. Hogarth Flyover was reopened to the public on 31 August 2014, 10 h ahead of schedule. This paper outlines the logistical and technical challenges that were encountered in ensuring that the flyover remained open despite its condition and returning it to a condition fit for its status as a strategic infrastructure asset.