To deal with fallen leaves on the railway, you can use lasers placed in front of.
Wet leaves form a very tight and slippery coating on the rails, similar to Teflon. This poses a threat: the adhesion between the wheels and the rails decreases, and the braking distance increases. Leaves interfere sensor is removed information about the state of the way.
Most of the transport companies used for this purpose pressure washers, cleaning the leaves with water. Method effective, but has disadvantages: washing damage the rails and substrate underneath.
The first to use a laser became British in 2003, this has spurred their train accident in 2000 and the problems that film leaves delivered freight trains.