Some people are accustomed to “jumping on the bus” – another way to say climbing aboard. But how does something as heavy as a transit bus jump ahead of traffic at a busy intersection? And why would it want to?
The reason for jumping ahead of other vehicles is that it helps buses (and transit riders) stay on schedule, and we’ve got a hand in making it happen. It begins with analysis by the Ministry of Transportation and Infrastructure’s traffic engineers. They look at intersections in urban areas that experience traffic congestion at peak times, and determine if a “bus queue jump” can be safely installed to improve transit flow.
If the answer is “yes,” a queue jump is created by designing and building a pull-out lane for transit vehicles. This enables the bus to leave a congested lane, turn into the shoulder lane and drive up alongside traffic lined up at the lights.
The next step to developing a “bus queue jump” is adding an additional white traffic signal to the top of the typical red, yellow and green light arrangement. When the bus pulls up to the intersection, three loop sensors in the road detect the bus’ presence at the signal. Then, at a time coordinated with the intersection’s other traffic signals, the white light rectangle flashes for a set time, usually about 5 to 11 seconds. This tells the bus driver to accelerate through the intersection and go back into the main lane – “jumping ahead” of the traffic queue which continues to have a red light.
The traffic management system (also known as “leapfrogging”) reduces delays and helps keep buses on time, giving transit riders greater certainty about when they’ll be picked up by the bus, and what time they’ll reach their stop. So, queue jumps contribute to reliability and time efficiency for transit – good incentives for people to use the bus system. This encourages commuters to leave their cars at home, thereby also reducing greenhouse gases.
Next time you spot a “bus priority signal” sign like the one pictured here, check if there’s a bus beside or in front of you, and you might actually see it jump ahead of the queue!