Buses vs Trams
There’s a fantastically interesting post over at Human Transit on comparing the benefits of buses and streetcars (trams), and how it is easy to get blinded by the romance of streetcars rather than looking at the transit problem we are trying to solve and then going about the best way to fix it. Jarrett Walker, a well respected transport consultant who writes this excellent blog, outlines his observation (after making a seriously large number of disclaimers):
Streetcars that replace bus lines are not a mobility improvement. If you replace a bus with a streetcar on the same route, nobody will be able to get anywhere any faster than they could before. This makes streetcars quite different from most of the other transit investments being discussed today. Where a streetcar is faster or more reliable than the bus route it replaced, this is because other improvements were made at the same time — improvements that could just as well have been made for the bus route. These improvements may have been politically packaged as part of the streetcar project, but they were logically independent, so their benefits are not really benefits of the streetcar as compared to the bus.
While we tend not to have this discussion particularly often in New Zealand, because there aren’t any tram systems left (apart from a tourist circuit in Christchurch), trams may well form an important part of future public transport investment, so it’s crucial to have a decent look at whether or not they’re worth the (significant) investment. What is crucial to remember here is that the blog post is only talking about “mobility improvements” and not the potential wider benefits of tram systems. Unlike trains that run in their own exclusive corridors, trams tend not to be able to travel faster than buses, and are not necessarily more reliable. Clearly, if a tram is able to travel within its own right-of-way then it will be faster than a bus that gets stuck in general traffic – however the speed differential is due to the right-of-way issue and not the fact that it’s a tram. Comparing speeds of a tram with those of a bus lane would give a more realistic outcome, and probably tell us that the bus was quite likely faster. Gosh, this is all sounding quite heretic at the moment coming from someone like me. Like most public transport advocates I do consider trams or streetcars to be superior to buses, but it is certainly necessary for me to ask the question “why”? Is it just because trams are cooler? Is it just because buses are all a bit boring, smelly and noisy? Is it some hazy nostalgia that wants to recreate how cities were in the early 20th century? The telling thing is that the answer to all the above questions is “no”. While trams are cooler and there may be some nostalgia attached to my desire to see them reintroduced to Auckland, there are some very compelling reasons to invest in trams rather than the cheaper and easier option of only buses. Human Transit outlines those reasons quite clearly, by saying what the paragraph quoted above it clearly NOT stating:
I’m not disputing the ridership benefits of streetcars. Streetcars do attract more ridership than the buses they replace, though it’s not always clear why. There’s an urgent need for more research on how much of the ridership benefits of a streetcar are truly results of intrinsic benefits of the streetcar (such as the ride quality, the legibility provided by tracks in the street, etc) as opposed to results of other improvements introduced at the same time (including speed and reliability improvements, better public information, off-board fare collection, and possible differences in operations culture). I’m not saying that streetcars don’t promote urban development; clearly they seem to be doing that, though there’s room for disagreement about how much the development really requires the streetcar. I’m not saying that electric streetcars aren’t quieter and more environmentally friendly than diesel buses; clearly they are, but if this is your only reason for wanting streetcars, electric trolleybuses may meet your need less expensively. I’m not saying that streetcars aren’t fun to ride. They are.
While the “fun to ride” aspect might be a little trivial, the other three are critically important reasons why trams may be the best transit option even though they don’t necessarily provide a faster journey than a bus. Attracting more ridership than the buses they replace is a crucial sign that investment in trams can very much be worthwhile. A key aspect of this is that developing a tram-line forces an upgrade of the corridor that it runs along – you simply can’t use the current bus stops and you simply can’t get away with not upgrading the road while you put the tram line in. The second issue, promoting urban development, is perhaps the most significant benefit of investing in trams rather than buses. A tramline provides certainty that services will continue to be run along that route, that they will be provided at a decent frequency (due to the significant capital investment in constructing the tracks) and also provides a “legibility” to the route – that is the route is easy to understand. You know where it will go without having to acquire complex route maps. Finally, the quietness and environmental friendliness of trams cannot be under-estimated. If oil prices do skyrocket in the future then the price of fuelling all our diesel buses will also go up, therefore driving fares up to compensate for the higher cost. If we have an electric streetcar network then we can escape the effects of the oil spike, and public transport can have a cost-advantage over private vehicles. Trolleybuses may be cheaper, but they don’t provide as many benefits. This is not to say that I don’t agree with what Jarrett is saying in his post – in fact I most certainly agree with pretty much everything he says. Furthermore, I actually think that his argument is – in a slightly strangely ironic way – very supportive of investment in tram networks. This is because what the post effectively says is “don’t base your arguments for a streetcar network on mobility benefits, because it’s unlikely you’ll find any compared to buses – instead focus on the wider benefits of streetcars and you will have much more luck in finding some real benefits”. Finally, I also very strongly agree with what he says later in his post about ensuring that you don’t go into a transit project with a set prefered outcome already in mind:
But when the thinking starts with the love of one technology, you’re in danger of producing an inferior transit service, because when compromise needs to be made, technology-first thinking will tend to sacrifice the goals to save the technology. To use my previous analogy, you’ll build an inferior house because you weren’t really focused on building the house, you were focused on how much you like your hammer. Another way of describing technology-first thinking is that it tends to select and emphasise goals that the favored technology is good at meeting. In our house analogy, it’s as if we told our architect: “design me a house that will require hammering lots of nails!” If a community really does rise up as one and say “the goals served by the streetcar happen to be exactly our goals!” then they should have a streetcar. But too often, the technology advocate ends up sifting the goals based on whether they fit his technology, rather than whether they’re the community’s real goals.
On some corridors in Auckland I do believe a tram line would work very well – along Tamaki Drive and Dominion Road, for example. In the case of Tamaki Drive the legibility and quality of ride would encourage many tourists and recreational travellers to use the tramline who would have otherwise driven, while in the case of Dominion Road I think that a tram-line could encourage significant intensification and redevelopment along this corridor. In neither case is “enhancing mobility” the key argument for conversion to a tram, but in my opinion both cases have a strong justification for a tram line. In other corridors, say Onewa Road for example, I don’t think a tram-line would work as well (even though a large number of buses travel along it each day). This is because once you get to the top of Onewa Road the bus routes branch everywhere – meaning that you would either need to run tram lines all the way to Beach Haven and Glenfield (an enormous cost) or you’d force people into transfering from their bus onto a tram at Highbury shops constantly.
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