A concept – or perhaps more appropriately a term – that has been coming up a lot lately is the idea of trackless trains. If you look at my previous post about the draft Canterbury Regional Public Transport Plan, the idea of trackless trains or trackless trams is brought up in reference to the development of rapid corridors in Christchurch. I don’t want to get into the details of trackless trains, but I do want to quickly explore the idea of getting the choice of mode right.
In New Zealand right now we have light rail planned for Auckland, a light rail proposal in Wellington, and the early stages of investigation going on for rapid transit (potentially light rail) in Christchurch. In all these cases, alternatives to light rail have been, or will be, investigated. In addition to light rail, bus rapid transit (BRT) is a popular alternative, and there is already an example operating in Auckland in the form of the Northern Busway on the North Shore. BRT is great, I’ve used it in Auckland and Brisbane as well as a few other overseas examples and I really like what I experienced. However, BRT can have its drawbacks, one of the principle drawbacks being that it can be used as a way of being seen to do something (and cheaply) but not really doing much at all. This is what is often called “bus creep”. Basically, it works like this – what starts out as a true BRT proposal is cut back as the project progresses. Instead of a dedicated right-of-way corridor the whole length of the route, it becomes only part dedicated. Then, that corridor is cut down to being just glorified bus lanes, with priority signals at intersections. Existing bus routes continue to use the route, causing congestion, and all you’ve really done in the end is introduce a new frequent service, with higher capacity buses at best, and a slightly improved bus route.
Take Brisbane for example, where the existing busways are reaching saturation point in the inner city. The plan to unbundle this gridlock is to introduce a Brisbane “Metro“. It was originally touted as a sort-of true metro, using driverless, rubber-tired trains or trams, but has essentially ended up being large bi-articulated buses (that look like light-rail vehicles) running on the existing busway (alongside other buses) with a new section under part of the CBD. Don’t get me wrong, this is still great, as it will increase the capacity within the inner-city areas while freeing up space for other bus routes. However, it stands to reason that rubber-tired trains are basically… well, they’re basically buses.
So, with these two things in mind, when you look at an existing road space and want to put rapid transit on it, you can do the following: you can go the BRT route, with possible bus creep and a limitation on capacity, or you can go the whole high and build a light rail right-of-way, which will be more expensive but have a much higher capacity. Additionally, because light rail requires the expense of laying rails, installing a power source, and signalling etc, it will not likely suffer much “light rail creep”. This is probably why light rail leads to a greater level of transit oriented development.
However, there is a third way that is starting to creep into planning documents, and this is the idea of trackless trains or trams. However, as I’ve described using the Brisbane example, they are in reality just large buses, and I don’t think they should considered a separate form of rapid transit. And here is why I have a problem with them being elevated alongside light rail and BRT; in the case of Brisbane, the “trackless trains” would have been (or are being) introduced on high quality, grade separated, busways that were already built (except for the CBD additions). Essentially, Brisbane was (and is) basically proposing to bring their BRT up to the highest level they could. Much like BRT, the trackless train is subject to bus creep. It’s only really that much cheaper if you go the cheap and nasty option. Sure, you can tout that they only require painted lines on the road to delineate their route, meaning no expense of laying rail. That sounds great, but what are you getting? That doesn’t sound like rapid transit to me, that sounds like spin.
Technological advances in the transport sector are great, but too often ideas and concepts are promoted as some kind of silver bullet that will The problem is we are easily captured by buzzwords that make things sound great, cheap, and progressive, when really they are nothing of the sort. Trackless trains aren’t a totally stupid idea, they just have to be bloody good in execution. Rubber-tired metros are a real thing, and I rode the Montreal Metro a few times on a visit tot he Canadian city last year. However, those trains aren’t buses, the infrastructure is as good and dedicated as any other metro I’ve ever ridden on. We have to be careful that nice-sounding terms aren’t being used to capture people to ideas that just don’t cut the mustard.