When a traffic signal is located within 60m of a heavy rail train crossing, Transport Canada requires the signal to be “pre-empted.” Before the bells, crossing gates, and flashing lights are activated, the traffic signal lights will enter a short phase designed to allow vehicles to move out of the way, before the gates come down.
In Calgary, The City’s practice is to consider these regulations when designing light rail crossings as well. Some traffic signals will include an LRT pre-emption phase when rail lines cross one or more legs of an intersection near a traffic signal. This “track clearance phase” prevents a train or crossing gate from hitting a vehicle or pedestrian.
A driver who is crossing train tracks will see this “track clearance phase” as the green traffic light that comes on before the gates come down. The gates will then descend, even while the traffic signal light is still green. Vehicles already on the tracks or past the tracks can then proceed safely, while approaching vehicles are prevented from driving on to the tracks.
If you see both a green traffic signal light, and flashing red train crossing lights;
- Do not cross the tracks if you can come to a safe stop before the gates
- Proceed forward only if you are already on the tracks, or past the tracks
Trains in Calgary will approach intersections frequently and with little notice. This will sometimes result in:
- shorter green light
- shorter walk light, or
- unexpected “skipping” of your turn
This inconvenience is necessary to ensure the safe track clearance time is implemented before the train arrives.