Level Crossings
Level crossings present a unique challenge: the intersection of the railway environment, where trains cannot stop quickly, with the public highway system.
Warning and Protection Systems
Level crossings rely on robust detection and warning infrastructure. When an approaching train triggers a track circuit or treadle (the 'strike-in' point), the crossing sequence begins.
- Active Crossings: Utilize warning lights (wig-wags), audible alarms, and physical barriers (half or full) tied into the signalling system.
- Passive Crossings: Rely on clear sightlines, signage, and the road user's vigilance. These are typically limited to very low-speed or rural lines.
In full-barrier crossings, the crossing must be proven 'clear' (either by CCTV monitoring from a control centre or automated obstacle detection radar) before the protecting railway signal can clear for the train.