We’re now only months away from the opening of New Zealand’s biggest transport project to date, the Waterview tunnels – likely to be sometime between January and March. Waterview should have represented the last major new urban highway connection in Auckland but of course the NZTA and others have since started pushing other projects such as the East-West Link and an Additional Waitemata Harbour crossing.
While there are some positive things to the project, we’ve been concerned for some time about the impact the project will have across a number of areas, in particular the ongoing operational cost of the infrastructure and the traffic impacts. The concern for the latter issue was further strengthened by comments in the April Auckland Transport board report talking about how an Operational Risk Assessment had looked at expected traffic demand and that some additional physical mitigation works were needed and that workshops were taking place between AT and the NZTA. So I decided to OIA the information.
First up the issue of operational costs. Here’s what the NZTA said in response.
The latest cost estimate for Waterview Tunnels to maintain and operate on an annual basis is approximately $16 million.
To put that $16 million in perspective, in the 2014/15 financial year, the last for which data is currently available, the NZTA spent $108 million to operate, maintain and renwe the entire State Highway network in Auckland (up from about $90 million in the few years prior to that). That means the new Waterview Tunnels add almost 15% to the annual state highway operational bill in Auckland. Diving a bit deeper, the Auckland State Highway network is 1048km in length (by lane km). Waterview adds about 24km to that total, an increase of just over 2%. I guess what this highlights is that tunnels are really expensive, not only to build but also to operate.
On to the Operational Risk Analysis
We’ve long noted that one of the outcomes of Waterview is that it is likely to create a lot more pressure on the motorway network, especially east of Waterview as people from the southern isthmus use the new connection to drive towards the city or North Shore. When combined with all of the existing and new traffic from the west it’s likely to cause a lot of issues. We’ve also heard suggestions that for safety purposes the NZTA don’t want cars stopping in the tunnels because as I understand it, the ventilation system is designed based on moving vehicles to help push air through the tunnels so it can exhaust the fumes – happy to be corrected on this though.
Regardless it looks like we were right to be concerned and the NZTA are now pushing through a number of mitigation measures to state highways and local roads in a bid to boost vehicle capacity, possibly at the expense of PT and cycle infrastructure and potentially including the Northwest busway. What’s also not clear is why all of these mitigation measures wasn’t part of the initial assessment for project to begin with.
The Operational Risk Analysis is essentially a heap of new traffic modelling to try and determine if and where any issues might arise within the first six months and to test potential options to mitigate those issues. It’s the result of NZTA wanting to avoid the operational and reputational risk from something like a repeat of back in 2010 when they opened the SH20 to SH1 link at Manukau and finding it caused a heap of issues that they’re only now working to fix.
The modelling, which makes up the bulk of the report, highlights the areas of concern and is also assessed against three groups of mitigation measures – a summary of these mitigation groups are shown below.
Ultimately the report recommends focusing on the Group 2 mitigations. These are:
It is strongly recommended that as many of the individual mitigations from Group 2 as possible be implemented prior to the opening of the WVT to manage the risks associated with tunnel operations and the operational and associated reputational risk that accompanies such a significant change to the configuration of the network.
Specific actions are recommended as follows:
- Urgently engage with Auckland Transport to investigate if minor arterial corridor mitigations could provide a small increase in off ramp discharge capacity at the following three locations:
- Maioro Street northbound off ramp.
- Te Atatu Road westbound off ramp.
- Royal Road westbound off ramp.
- Design an additional lane at the following locations (using existing hard shoulders where feasible) to enable implementation prior to WVT opening:
- SH20 southbound from Maioro Street on ramp to Hillsborough Rd on ramp.
- SH20 northbound from Orpheus Drive on ramp to Queenstown Rd off ramp.
- SH20 northbound auxiliary lane on approach to Maioro Street off ramp.
- SH16 eastbound to from WVT to Western Springs off ramp and from Western Springs on ramp to tie-in to the existing five lane section near the Bond Street Bridge.
- Carry out further assessment on the following:
- Potential for operating some or all of the additional lanes recommended above as dynamic part-time (hard shoulder running) lanes.
- Potential three laning between Lincoln Road and Royal Road (both directions).
- Potential northbound auxiliary lanes on SH20 from Puhinui Rd on ramp to Massey off ramp and from Massey on ramp to SH20A off ramp.
- Minor layout changes at CMJ:
- Ramp signaling the SH16 eastbound to SH1 northbound and Port to SH1 northbound links separately.
- Re-configuring the SH16 eastbound approach to CMJ to allow two lanes for AM peak queuing for the SH1 southbound link (merging to one lane before joining SH1) at the expense of one of the lanes leading to the port.
A second part of this assessment has still to be completed. This will relate to assessment of abnormal operations, mainly incidents. This assessment will include assessment of operating additional lanes as dynamic part-time running lanes (Hard Shoulder Running) to assist in incident management.
This is also shown in the diagram below
Below is an example of one of the modelling outputs It is a heatmap showing where, when the severity of congestion based on a scenario to a specific level of extra demand. As you can see the modelling suggests significant improvements to the motorway.
There is no mention of just how much this mitigation will cost although the NZTA claim it will achieve $15 million in travel time savings per year.
The OIA also includes the minutes from a couple of workshops and they too contain some interesting information. I’ve just extracted a couple of items from each paper which are shown with the bullet points. The names/initials of the participants except for those from the NZTA have been removed so I’ve just used XX as a replacement.
There’s a concern that because the NZTA are focusing on pumping as many cars off the motorways as possible it might now affect bus routes.
- XX explained there would be more bus routes and increased frequency especially around Te Atatu and Lincoln Road. He expressed concern about the future reliability of these new services in light of the risk of congestion following the opening Waterview Connection
It sounds like AT want bus lanes or other layout changes to Blockhouse Bay Rd but that possibly the NZTA want it kept as is just in case something goes wrong with the tunnels.
- XX mentioned that AT would be protecting Nelson Street capacity during peak times (CBD tactical team to maintain off-ramp capacity) from the motorway and with respect to planned work on the AT network. AT want to do any major maintenance work either before tunnel opening e.g. City bound buses lanes proposed for Blockhouse Bay Road.
- XX mentioned that Blockhouse Bay Road would be a planned and incident diversion route for Waterview Tunnel closures and that if AT propose to reassign capacity, freed up by Waterview Connection, then these intentions of use of Blockhouse Bay Road could be in direct conflict with each other.
Given this was in March of this year, how on earth were the NZTA not aware AT were looking at busway options for SH16?
- XX talked about the need to consider the northwest busway with respect to the mitigation projects. XX mentioned there were some ‘medium term’ busway proposals to consider which include shoulder bus provision and highlighted a possible conflict.
- XX NZTA now aware of a possible busway, need to know details and have a recommendation before deciding if there is a conflict. This has been passed on to the transport planning team at The Agency.
The minutes don’t say which school but given most of the focus seems to be around the Maioro St interchange, I’m guessing this refers to Wesley Intermediate. Why the school wouldn’t want kids to be safer is absurd.
- XX said that the school did not support a mid-block crossing and preferred the provision to be provided at the intersection itself.
It seems the NZTA are planning a full interchange at Northside Dr near Westgate
- GO, XX provided an update on Northside drive proposals, including consideration for a full diamond interchange.
So all up it seems we have the NZTA rushing to trying and add more motorway and local road capacity in a desperate bid to stop the shiny new centrepiece of their system from getting congested. What do you think of the papers?