Work on Reading 'train flyover' under way
11 December 2013 Last updated at 15:50 GMT
Work is under way on a train viaduct in Reading designed to ease the region's biggest rail bottleneck.
At 2km (1.25 miles) long, it is a key element of the £950m project to transform the Great Western main line.
Network Rail said the viaduct, located to the west of the station, will make a "huge difference" by separating mainline trains from freight trains.