SLA: Signal for railway level crossing without barriers
The SLA are optical and acoustic signals for level crossings with class “B” protection (without barriers).
They are installed at intersections between urban or interurban roads and railroad tracks, oriented towards vehicles. Normally four units are placed at each level crossing (two in each direction of the track).
They consist of two 300 mm diameter red LED spotlights, a red LED message with the message “ANOTHER TRAIN” and an acoustic signal.