Colinton Bridge, also referred to as Colinton Viaduct, carries the B701 over the Water of Leith as it threads its way through a narrow gorge to the south west of Edinburgh. The multi-span bridge not only crosses the river, with a pier in the riverbed, but also the parkland on either side, part of which was formerly the route of a railway line which passed under the western arch.
Before the City Bypass was opened in 1982, Colinton Bridge carried the A720 traffic, and as the B701 was the last road before the Pentland Hills started, it was a very busy route. This probably explains the cantilevered concrete extensions on either side, which carry the pavements. Rather unusually, additional small cantilevers are used to mount the street lighting on, behind the railings! While these extensions didn't substantially widen the roadway, they allowed pedestrians to safely cross the river without having to dodge the traffic.
