Late buses occur because bus routes are inherently unstable. When the buses are on schedule, everything seems to work fine. They travel from stop to stop, waiting at each for passengers to board or alight; however, once a bus gets behind schedule (i.e. construction delays, traffic accidents, etc.), its nearly impossible for it to get back on track (affecting the entire system, because – interlining).

When something like a construction project is going on, it’s best to compare the bus to a car, rather than a train. When one bus is experiencing delays because of traffic, there is very little that the driver can do to make up time – compared to a rapid or train line which is entirely removed from the situation because they are travelling along an entirely different transportation network.

Interlining combines two or more independent transit routes into one operational schedule. Buses are interlined for a number of different reasons, but one of the main reasons is scheduling efficiencies – interlining buses help us minimize the footprint we use; a bus can arrive downtown as one route and sit for just a few minutes and then leave as the next scheduled trip on another route.

Wouldn’t it be most efficient if the buses ran nonstop – an operator drives his route and immediately goes back the opposite direction? Unfortunately, no.

If you run buses nonstop you would no longer have a fixed schedule; riders require a schedule so they can make transfers to other services and have some idea of bus arrival at their stop. Without a schedule riders wouldn’t know when to expect the buses.

One of the challenges of interlining is that incidents or construction delays, for example, the slowing down Route 1 could result in a delay in service on route 9. However, with any serious delay, the operating company is involved from the beginning and is in communication with the City to makes adjustments on the road to ensure that service interruptions are minimal.

Bus bunching happens because, if a bus gets delayed, then there will be more people waiting at the next stop than anticipated. The extra passengers’ boarding time makes the bus even later, and so on in a vicious cycle.

To combat bus bunching, bus systems have to build slack into the system, but that slack involves extra buses and labour and longer travel times.