Ottawa is moving forward with a plan to replace its partial busway network with light rail, including a new tunnel under downtown. As usual, The Transport Politic provides a well-linked overview of the issue. So this is probably my last relevant chance to talk about my tour and observations of the busway in 2006. I took a particular interest in this busway because it is the conceptual ancestor of the busway network now being built in Brisbane, and the basis for the "Quickways" concept advocated in the US by Alan Hoffman.
I have two really strong impressions of the Ottawa busway. Both may be relevant to understanding why Ottawa is moving on with a conversion to rail, and why Brisbane shows no signs of doing so.
In this post, I'll talk about the main structural problem with Ottawa's busway. In the next post tomorrow, I'll discuss an aesthetic one.
The structural problem is simple: the downtown segment of the busway system was never built. Buses flow through fully separated busways extending in three directions from the city, but all these buses are then dumped into the same one-way couplet, Albert and Slater Streets, when they get downtown. More remarkably, all these buses stop at the same stops. And when you tell around 100 buses per hour to stop at the same stop, you get this:
It needs to be noted that this situation was not an inevitable consequence of the busway, or of the decision not to build a bus tunnel under downtown, as Seattle and Brisbane did. It was the consequence of a decision not to give the buses the space they would need to move across downtown efficiently. When you are talking about well over 100 buses per hour, the only fully reliable on-street solution is a double-width exclusive bus lane with skip stops (different groups of routes stopping at different stops, which alternate as you go along the street).
It worked on the pre-rail Portland Mall, it works on Seattle's 3rd Avenue, and it will soon be working in Minneapolis, as I discussed here. Double-width exclusive lanes can comfortably move about 180 buses per hour, with no more than two buses piling up at any one stop. The way they do this is simple: they insure that buses never block each other; when a bus is stopped, other buses can pass it.
You also have to insist that the lanes not be shared with turning cars, as happens in Ottawa. Most commonly -- as in Portland, Seattle, and Minneapolis -- there are no parallel car lanes, or if there are, turns across the bus lanes are not permitted. That way you don't get a pile of buses behind one right-turning SUV.
A double bus lane is obviously a challenge to advocate, mostly because it commandeers a large share of the street. Obviously, you make the case for it, if you can, by showing how many people will move through the bus lanes on buses, compared to how many will move through the car lanes in cars.
There is no reason to question Ottawa's decision to move on to light rail. Light rail will certainly deliver better outcomes in terms of emissions, energy efficiency, and a more efficient utilization of labor, all critical features to the modern transit system.
But I do object to using this case as a basis for anti-busway triumphalism. When people claim that that Ottawa's light rail decision proves the failure of busways, I'd reply that you can't judge a busway network that was missing its most important link. It would be as if you had chopped off the roots of a sapling before you planted it, then watched it die and said: "See? What did I tell you? Trees just don't work!"