[LINK] "Rocket Talk: How Come Streetcars and Buses Bunch Up?"

[rfmcdonald]

In a new feature at Torontoist, TTC chief Adam Giambrone and Director of Communication Brad Ross will be answering questions about the TTC. In today's post, they'll be explaining why buses and streetcars bunch up, with two or three or four vehicles coming in quick succession in the space of a couple of minutes and leaving the route without serve for twenty or thirty minutes, leaving the people who were so stupid to wait for it--say, for the 29 Dufferin--stranded and left to get in late to work much to the manager's displeasure. Not that I'd know anything about that, of course.

Service reliability—having buses, streetcars, and subways come as often as they are supposed to, and on a regular and predictable basis—is one of the most important parts of providing good quality transit. This is reasonably easy to achieve when the service is operating in its own private space—like subways in their own tunnel, or LRT in a dedicated right-of-way—and you have almost complete control over what goes on in that space.

However, when buses and streetcars have to operate on public roads, and compete for space with everything from private cars to courier trucks, they have almost no control over what goes on in that space, so it becomes much more difficult to ensure that the service will be regular and reliable. Often, buses or streetcars get delayed, causing a “gap” in service.

Once a bus or streetcar falls behind, the problem “snowballs” because more and more people end up waiting at the stops, and it takes longer for these bigger crowds to get on board, so the streetcar falls even further behind, and so on. The streetcars behind the delayed one catch up, the streetcars become bunched together and, when they finally arrive at the stop, they are in twos or threes.

There's much more at Torontoist.