Many left turn lanes in Vancouver are quite long and are equipped with 2 sets of traffic sensors.
This means if there’s only 1 car waiting in the left turn lane when the light is red, then the car will not get the advanced left turning arrow; if there are “several” cars in the lane, then the traffic light will “know” and the vehicles will get the left turning arrow (designed for efficiency). In some cases (if you get on the sensor early enough) you can simply stop on the 2nd sensor and then magically receive your left turning arrow. This is definitely not something I make a point of teaching people, but hey it might be good to know, especially for the pizza delivery person.
The first sensor:
The other sensor: