COMMUTERS on the Tyne and Wear Metro experienced delays this morning due to 'low rail adhesion' or leaves on track as it's more commonly known.

The firm apologised for the delays and offered this explanation as to why such a seemingly trivial obstruction causes problems for rail companies across the world.

They said: "When leaves fall on to the line, particularly in damp and wet weather, the rolling action of passing wheels compresses them, causing a greasy 'mulch' to cover the top of the rail.

"It reduces the adhesion, between the steel train wheels and the rails. Acceleration must be reduced to prevent the wheels from slipping, and braking distances extended, causing trains to run slower than normal.

"Leaf fall disruption is an issue affecting train companies globally. Metro is particularly susceptible with light-weight carriages, rapid acceleration and frequent stops."