Every weekend we dig into the archives. This post, which is quite topical given announcements on Thursday, was first published in August 2016.
Auckland Transport have published a new version of their airport rail video, essentially stripping out the heavy rail parts while also adding a little bit more detail about the airport.
Perhaps one of the more interesting aspects is it shows a bit of how light rail would get through Onehunga. It appears the plan is to elevate the light rail line over Neilson St right where AT are about to remove the bridge that lifts the road over the rail corridor.
Every time rail to the airport is discussed, here or in other places, there are a number of people who question AT’s decision to use Light Rail to connect to the airport. The biggest complaints/misconceptions I’ve seen against the idea of using light rail to the airport are:
- Light rail is slower – especially on Dominion Rd with lots of stops
- That it will be like Melbourne mixed traffic
- Light rail doesn’t have enough capacity
- It will mix with trips on Dominion Rd
- It’s light and so heavy must equal bigger and better
So let’s step through some of these and to do so, I’m going to use Seattle as an example. The reason for using Seattle is that its Link Light Rail has many characteristics that appear to be almost identical to what Auckland Transport is proposing.
First a little bit about the system.
Seattle has only recently started building its light rail system and the first section opened in July 2009. Since then there have been a couple of extensions, to the airport in the south (six months later) and just in March this year, a 5km, 2 station extension to the north. Further extensions in each direction are already under construction with other lines and extensions planned.
As of now the entire light rail system is just over 30km in length which is almost identical to the distance between Papakura and Britomart. It does have fewer stations though and outside of the city, much wider station spacing. The route is a mix of grade separated right of way with a mix of tunnels and bridges, median running and in the city centre it shares one tunnel with buses. Below is an image from Streetview showing Martin Luther King Jr Way which a 6.2km long section of median running and is similar to what we can expect along Dominion Rd. As you can see it is not mixed with traffic and the rail is separated from the road by a small kerb. Access across the tracks at intersections is controlled by lights.
The light rail vehicles used in Seattle are capable of speeds up to 105km/h which at maximum is only 5km slower than our heavy rail trains are capable of, and which ours don’t often get close to achieving in normal service. Seattle has some fairly lengthy sections which over which I imagine it is able to make the most of it’s speed. That means it only takes about 44 minutes to travel the 30km for an impressive average speed of just over 40km/h. That is about the same average speed as the Eastern line from Manukau but considerably faster on average than the Southern, Onehunga and Western lines, the latter two average less than 30km.h.
Even if you exclude the section from the Airport to Rainier Beach and from Westlake to the University of Washington, the system achieves similar average speeds to our network.
Obviously our existing trains need to be faster but that is a discussion for a separate post. What is clear is that at the very least, it is possible to get light rail up to a similar speed as what we’re achieving now with our rail network.
To achieve the times Auckland Transport claim, LRT would only have to average 30km per hour, the same as being achieved on the Rainier Beach to Westlake section. With AT planning to create a corridor like shown above (but with a single traffic lane instead of two), that should be possible. There’ll be no light rail mixing with cars and also no stopping ever few hundred metres like many buses and many traditional tram networks such as Melbourne do.
It’s all very well saying that heavy rail has more capacity but just because you can build a rail line capable of running trains with a capacity for 1,000 people every 90 seconds, it doesn’t mean you should. It is very expensive both to build and run so most cities only do it if they absolutely need to. Better to build enough capacity for what you’re going to need (plus a bit of redundancy).
As we know, AT are planning on using up to 66m long light rail vehicles (two 33m coupled together) that can carry up to 450 people running every 5 minutes. Looking over at Seattle, they have 29m long vehicles that can carry around 200 people running at up to every 6 minutes in the peak. They too can couple vehicles together and until recently were limited to joining two trains together but their system allows for up to four to be coupled. Four vehicles connected together would be around 116m long and carry up to 800 people – more than one of our 6-car trains are designed to carry (ours carry 750 people). Given the technology is obviously already available, there doesn’t seem to be a technical reason why we eventually couldn’t see longer light rail trains here – assuming we designed for the possibility.
Another way of looking at capacity to see how it’s performing. Sound Transit who run the system publish ridership data monthly. The opening of the extension to the University of Washington in March has seen ridership soar at up to a staggering 83% compared to the same month a year prior. That means over the last few months, this single LRT line is carrying more than Auckland’s entire rail network combined. The results suggest that by the time the extension has been operative for a year that their system will be carrying 20 million+ trips a year. Seattle’s weekday numbers are about the same as what we have but they do much better on weekends, something we’ll hopefully see the new network improve.
On both speed and capacity, the example for Seattle shows that Light Rail can be every bit as good as our current heavy rail system. For me the key is not the name of the mode but how it’s designed. The pressure that needs to be applied to Auckland Transport, the council and the government is to provide the funding needed as soon as possible and to ensure that it’s implemented to the level advertised in the video above (or better). Light or heavy, it’s still rail to the airport.