I'm relieved to report that commenters who actually saw me give the presentation "A Field Guide to Transit Quarrels" seem to agree that I wasn't displaying a bias toward or against particular projects, except perhaps for projects that were based on misunderstanding or ignoring some basic geometry.
However, finally I have a comment that attacks me full-on, which gives me yet another opportunity to think about whether I do have a "modal bias." It's from commenter Carl, who I believe saw the presentation in Seattle:
My perception is that you have a mode bias toward bus and BRT, and that this comes out in your talk and writings. I don't know if there is a professional reason for this (perhaps this is your expertise and source of consulting engagements.) These are the reasons that I feel you have a mode bias towards bus and BRT:
1. You say that bus/BRT can be made "just like" rail - in vehicle appearance, fare payment, stations, exclusive right of way, etc. Embedded in that assertion is the fact that the typical features of rail are superior to the passenger comfort, which you don't fully acknowledge. But even if all these improvements are made, it may close the gap but it is still not rail.
If I've every used such a vague term as "just like" in discussing rail-bus distinctions, then I was just being lazy. I do believe, however, that there's such a thing as mobility, which consists of the ability of a network to get you to a wide range of places with a certain travel time and reliability, and which defines a transit system's ability to provide a sensation of freedom to those who choose to depend on it.
And I do contend that most of the features of a transit service that determine travel time and reliability are simply not about the rail-bus distinction. They are about frequency, stop spacing, boarding/alighting time, and the exclusivity of the right-of-way (what can get in your way). I've also pointed out that in mixed traffic, buses have a reliability advantage over streetcars because they can go around many minor obstructions that would trap the streetcar.
I've never contended that bus and rail are equivalent in matters of comfort, but they are certainly converging, becuase rail cars are defining the comfort standard that bus design aspires to. I agree that there will always be a ride quality difference. How much that matters, in the long run, will depend on all the other factors that influence our decisions about how to travel.
There are a few cases where mobility does arise directly from a technology choice:
- Capacity is one of the best technical reasons to build rail. If you routinely need to move more customers per driver than buses can do, you need rail so that you can run much longer vehicles. Capacity is the reason that the Los Angeles Orange Line probably will need to be rebuilt as light rail at some point.
- Frequency benefits hugely from driverless operation. This is currently an option only with rail (well, technically, fixed guideway) services.
2. You cite the lower cost of bus/BRT. The reason that bus/BRT is lower cost is that the investments aren't being made to create the ride quality and reliability. The primary advantage of bus/BRT is to use existing roads and require less investment -> lower experience. It's a valid trade-off for lower demand routes or if the resources can't be gotten, but the lower cost comes with lower quality, not equivalence.
I agree that if you compare rail to a completely closed busway, you can get similar costs if you design to similar standards. Some factors push one way and some the other: A busway tunnel has to be a little wider than a rail tunnel, for example, but rail has a power supply system and most busways don't.
But busways still have certain kinds of versatility that rail lacks. In the high-end BRT system in Brisbane, the busway itself was very expensive but the buses serving it flow through the end of the busway and onto various routes. This means that a large area has the benefit of the busway's speed without requiring a connection, and without requiring dedicated transit infrastructure on all those outer routes. This is a very specific and powerful feature of BRT that rail simply can't do.
3. You dismiss evidence that the riding public has a preference for rail and that rail on a given corridor (with enough latent demand) will attract 50%-100% more riders than bus service at the same frequency. (See http://de.wikipedia.org/wiki/Schienenbonus or the comments by the Munich transit planner on the Munich thread). You call this cultural or emotional, but if even riders make an emotional decision, the evidence is there that riders prefer rail and will ride rail in greater numbers.
I don't dismiss it at all. But to use the terms of my field guide, the intrinsic preference for rail is the reuslt of a combination of factors that are mostly cultural -- though ride quality has an element of the biological. The preference for rail observed in ridership is partly about ride quality, and that will always be better on rail. But it is also partly something that has been trained into the culture by the way rail and bus are often presented to the public, such as the message that rail systems are simple and buses are complicated. In other words, the preference for rail is partly about an intrinsic difference but partly an echo of the history of how these modes have been used.
What I see in fairly modern German and Swiss systems (Heidelberg and Bern come to mind) is a deliberate effort to make bus and tram feel as similar as possible. Other cities, notably Karlsruhe and Munich, seem more invested in maintaining a feeling of difference between bus and tram. Berlin displays impulses in both directions.
4. You dismiss the mode debate as political or emotional. If a corridor has traffic demand to support rail, the debate is often about whether to be cheap and under-invest in transit capacity (bus/BRT) vs. make the big investment in exclusive right of way and grade separation. The USA's most successful BRT right of way, LA's Orange Line, clearly should have been built as rail, which would give it higher capacity and lower operating costs.
Again, capacity needs, such as are coming up on the Orange Line, are a very solid reason to build rail rather than bus. Rail will always be better at carrying more passengers per driver, and in some cases doing without drivers entirely.
But I do not "dismiss the mode debate as political or emotional." I simply observe that emotional factors play strongly in technology debates, and that while these factors have their place, it's risky to let them get out of control when you're building long-term infrastructure.
Why? Look around your city and I bet you can find some long-term infrastructure that's not at all what you would build today, and that presents obvious practical problems for the life of the city now. Those facilities were designed to meet the emotional needs of a past generation, and some of these were built in spite of obvious mathematical or geometric absurdity because of the passion of the moment.
The US Interstate Highway System is full of examples. Why did the US build grade-separated interchanges at every farming road in North Dakota, so that I-94 could be built to Interstate standard instead of being just a really fast highway with some very minor intersections? Well, one answer is that the Interstate system was conceived as the Intersate and Defense Highway System, and defense is an emotive topic. After all, we might need to move tanks from Seattle to Miami without stopping, or even being delayed by a truck slowing down to turn onto a farming road. The Interstate system was driven by an emotional obsession with a single, consistent, national network, and this caused huge sums to be spent on things that no longer seem to have much value.
You can tell the same story about the rise of car-dependence in cities in the 1950s and 1960s, a period where we fell in love with cars to the point that we didn't foresee obvious geometric limitations on how many of them we could fit into a city. This simple geometry mistake led to a range of urban woes that many people, including myself, will spend their whole careers trying to undo.
Both of these highway examples are the same story: Things were built a certain way to meet the emotional needs of a moment in history. Today, the emotions have changed, but the geometry hasn't. So we're still stuck with the geometric consequences of those emotional decisions.
Emotions change, culture changes, priorities change, but geometry will never change. A project becomes risky when it starts trying to use the emotions it arouses to overwhelm geometry-based objections. Emotions will always play a role in technology choice. But it is in the nature of emotions to sweep us away, so sensible people just notice when that's happening and keep an eye on reality. They don't ignore emotional factors or oppose their influence, but they recognise them as emotional and keep them in perspective. It comes down to that age-old advice about teenage dating: "Keep one foot on the floor."