Track bed

Trackbeds of disused railways are sometimes used for recreational paths or new light rail links.

According to Network Rail, the trackbed is the layers of ballast and sub-ballast above a prepared subgrade/formation (see diagram).

It is designed primarily to reduce the stress on the subgrade.

Other definitions include the surface of the ballast on which the track is laid,[1] the area left after a track has been dismantled and the ballast removed[1] or the track formation beneath the ballast and above the natural ground.

[2] The trackbed can significantly influence the performance of the track, especially ride quality of passenger services.