Ever since Auckland Transport first started talking about light rail, initially just on the isthmus, it’s been shown as modern, low-floor vehicles, like you might find gliding through a European city. An attractive and exciting proposition for sure, one made even better with the new government have committed to it.
Since those initial plans, what light rail has been tasked to do has changed considerably. No longer are we just building a line on the isthmus but we’re going to be using light rail to play a key role in our regional rapid transit network.
What’s proposed is capable of fulfilling the tasks needed of it. However, over the weekend I was also thinking about how light rail can be a quite broad term covering many different types of vehicle. So, with this post I thought I’d look at a couple of them and ask if we should be considering them as options too. The key difference between these are the floor height.
100% low floor
This is what appears to be proposed and is increasingly common on modern systems. It’s what’s used on the Gold Coast, is being built in Sydney right now. Typically they have a floor just 300-350mm off the ground and so require a platform only slightly higher than a normal kerb to provide level boarding making it easy and unobtrusive to provide.
Typically they tend to have a top speed of 70-80km/h which is usually more than enough for most settings. Speed has often been cited in debates in the past about using heavy rail but even our trains, which have a top speed of 110km/h, don’t get above 80km/h all that often.
One downside is they usually have wheels attached to the chassis rather than on bogies like a train does and can make them a little noisier on some tight corners.
Some systems overseas retain level boarding off a low platform but have a raised section at the ends of the vehicles over the wheels. This is much like we have with the middle ‘trailer’ car on our trains. This is typically used on some of the older American light rail systems (but some newer ones too). The advantage of looking at an option like this is that it can allow for the vehicles to have bogies like a train, allowing it to handle corners easier and therefore faster. One of the more recent examples is the Seattle Light Rail which can reach speeds of over 100km/h. That extra bit of speed might be useful on some of the longer stretches out to the Airport, Northwest and the North Shore.
There are some systems that use high-floor light rail to keep level boarding to get the advantages of using bogies but to avoid having steps inside the carriage. The downside to this is that you can’t just have a high kerb but instead need raised platforms for passengers to be able to get on and off. Perhaps a flip side to this is it could make stations more prominent and more of a ‘rail’ feel. Particularly useful for those thinking we’re just talking spruced up trams here.
Some of the modern units of these can look decent, such as the latest units being used in Los Angeles. The system there also happens to be called Metro Rail which is also a probably more accurate description of just what it is than light rail. I’d think most people would probably consider that more train than tram
While there are certainly some benefits of this approach, I’d be highly sceptical of the idea of putting raised platforms at a number of locations down Queen St.
I assume that most of the focus on light rail has been on getting the project approved rather than the specifics of the vehicle, and fair enough too. As the project moves closer to becoming a reality it would be a good idea to ensure we’re thinking about just what type of vehicle and experience we want to achieve, not just for the first section but for future, much expanded network. I suspect this will most likely be the 100% low-floor option though.