Some big news out of Wellington yesterday with the release of the Public Transport Spine Study as well as more news on the Basin Flyover and Duplicate Mt Victoria Tunnel. Both are actually fairly intricately tied together. Here are the two press releases from the NZTA about the spine study (why did we need two). First let’s look at the PT spine study. It was described by the Greater Wellington Regional Council (GWRC) as:
The Public Transport Spine Study (PTSS) is about determining what a future public transport solution for Wellington city might be – one that is high quality, modern and meets the longer term aspirations and demands of our city.
The study has been undertaken by AECOM, and was commissioned jointly by Greater Wellington Regional Council, Wellington City Council and the NZ Transport Agency. These three agencies are working in partnership to ensure this work is aligned with economic and transport developments in Wellington City and the wider region.
This PTSS is a key action from the Ngauranga to Airport Corridor Plan (2008), which seeks major improvements to public transport to provide a high quality, reliable and safe service between the Wellington Railway Station and the regional hospital. It sits alongside significant improvements to the strategic road network that are now being planned and designed as part of the RoNS programme and major upgrades to rail network.
The study initially looked at a number of different options from simple bus lanes all the way up to extending the existing heavy rail network. From there the options were narrowed down to three:
- Bus priority – $59 million, which involves more peak period bus lanes and priority traffic signals for buses, along the Golden Mile and Kent Terrace, through the Basin Reserve and along Adelaide Road to Newtown and through the Hataitai bus tunnel to Kilbirnie.
- Bus Rapid Transit (BRT) – $209 million, which involves a dedicated busway, for modern, higher capacity buses separated from other traffic as much as possible, along the Golden Mile and Kent/Cambridge Terrace then around the Basin Reserve and along Adelaide Road to Newtown and through the (duplicated) Mt Victoria tunnel to Kilbirnie.
- Light Rail Transit (LRT) – $940 million, which involves new tram vehicles running on dedicated tracks along the Golden Mile, Kent and Cambridge Terraces then around the Basin Reserve along Adelaide Road to Newtown and through a separate Mt Victoria tunnel to Kilbirnie
One I noticed straight away which is odd is that the LRT option required its own tunnel under Mt Victoria whereas the BRT option was using the duplicated road tunnel. I imagine that this is a large part of the cost difference between the two. The NZTA say that the road tunnels will be limited to 50kph so I’m not sure why buses can use it but why LRT can’t (the official reason given is concerns over fire and safety issues of LRT in mixed traffic – something that doesn’t seem to be a problem elsewhere in the world). It’s also worth noting that buses through the tunnels wouldn’t have any bus priority. One thing that is crucial to later on in this post is the report notes that buses would also be able to run in the LRT corridor. Anyway here are the routes that were assessed.
The report also contains cross sections of various parts of the routes showing where the lanes would be located within the street environment. For both the BRT and LRT options this means on either one side of the road or down the centre. But it isn’t just routes or modes that are important, so on to the impacts these options would have. As you would expect, each option seems to have been assessed multiple ways. The ones I’m most interested in are the impacts on patronage, travel times and the economic assessments.
The travel time savings for both the LRT and BRT options seem fairly impressive. From Kilbirnie these two options each save over 10 minutes while they also save 6-7 minutes from Newton.
Each option has been assessed at both a regional level and in the South and East, the area served by the infrastructure and here is where I think things get interesting. The modelling only looks at the AM peak period – something that has been happening in Auckland too – and even in the reference case shows patronage dropping between 2021 and 2031. Presumably this is caused by the RoNS making it easier to drive. At the regional level the report suggests that even the best performing option – BRT – will only add 900 passengers (2.6%) to the morning peak period by 2041. By comparison it suggests that LRT will only add 400 (1.1%).
The impact in the South and East gets even weirder with LRT only being suggested to increase patronage over the base case by 80 passengers (1.1%) compared to 220 (3.1%) for bus lanes or 550 (7.8%) for the BRT option.
To be honest, it wouldn’t surprise me if there is something funny going on in the modelling. We know from the CCFAS that our modelling of PT usage is very poor, and even after a lot of effort is put in to improving it. Considering that we don’t have any cities in New Zealand using LRT for PT purposes the impacts of it are probably not being assessed properly. Further when considering just how much time the BRT and LRT routes save, it seems even weirder that patronage numbers are so low.
All of the options appear to perform very poorly in an economic assessment however reading through some of the report it is clear that there is a massive issue identified in the standard assessment.
There is no limitation on the number of car trips that can be made to the CBD, the implication is that parking will increase to meet demand.
So effectively I read this as saying is that the RoNS will create a whole heap of road capacity which will encourage people to drive and that our economic assessments assume that more parking will magically appear in the city centre to cope with this. The report says that capping parking would increase the patronage from both the BRT and LRT options by 1600-2100 peak trips which is a fairly significant increase. Even with that in place the BRT option only just scrapes over the line.
One other comment from the press release caught my attention
The benefits are calculated using NZTA guidelines. These apply a monetary value to travel time savings experienced by existing and new public transport users and are offset by ‘disbenefits’ experienced by motorists because road space has been allocated to public transport.
Now I agree that when assessing these options the impact on road users from less road space being available needs to be taken into account however I would almost guarantee that the opposite thing isn’t taken into account when roads are being assessed.
Looking over all of the different aspects of the report it is fairly clear that the BRT option is what has come out on top. This doesn’t surprise me and as much as I might like to see light rail installed, even if it were half the price it just doesn’t seem feasible.
The other major piece of news mentioned is that hat NZTA has lodged applications to the Environmental Protection Authority for the Basin Flyover. They like to call it the Basin Bridge to make it sound cuter than it is but that doesn’t change the fact it is likely to end up a very imposing piece of infrastructure. This kind of thing is what cities around the world are now starting to tear down. Even the NZTAs own very pretty videos don’t make it look appealing – unless you are driving.