Thinking About State Highways
Safety, Resilience, Value for Money
What’s the problem?
I believe that today highway funding in New Zealand is being poorly managed. We could buy better outcomes for the same amount of money we spend on highways today. As I see it, the two core issues on the State Highways are they’re;
Dangerous
“In New Zealand for every 100 km stretch of high volume (>5000 vehicles per day), high speed (>70km/h), undivided sections of State highway, an average of 16 people are killed or seriously injured every year.” - NZTA
Fragile:
Slips and destroyed bridges are the main issues. Exhibited in the recent Cyclone Gabrielle and Upper North Island flooding which has cut communities off.
We see calls from transport advocates like Greater Auckland quite often to axe spending on new roading projects. Mill Road, Warkworth to Wellsford, Penlink, Otaki to Levin…. are seen as carbon and traffic inducing money pits. But we also see wide support for road safety and building community resilience. Given motorways or expressways are touted as the “safest roads”, and are less likely to be critically damaged in disasters, how are these ideas consistent?
There are lots of ways to increase the safety of the transport network. Lowering exposure by shifting trips and tonnage to rail, public transit or active modes. Or other system changes like better vehicles, more enforcement, and tougher licensing. But the core issue remains, it's too easy to make life ending mistakes on today's roading infrastructure.
How We’ve Solved This to Date
To improve safety and resilience, traditionally Waka Kotahi and politicians have loved the solution of a full bypass motorway on a new alignment, like Puhoi to Warkworth or the Kapati Expressway. From the country’s point of view this is usually a sub optimal solution because:
Most importantly, the opportunity costs. Money spent here is money not spent elsewhere.
It concentrates funding. Everywhere else languishes, with decreased maintenance, and a lack of funding for smaller improvements.
It's extremely expensive, hundreds of millions, or billions for each project. About 60 million per km.
They are usually net economic losers, costing more to build than the value they produce.
It leaves the old road and other connecting roads in an unimproved state.
A better solution
It would be better to improve the existing road alignments with:
Median wire rope barriers, and side barriers.
Ground improvements (retaining walls, soil nailing, drainage, rock armouring etc)
Lower speed limits where necessary.
Better intersections, roundabouts or turning bays.
Replacing direct access (driveways) with new side roads served by better intersections.
Upgraded bridges.
Waka Kotahi recently released footage from a truck dashcam showing the effectiveness of on-alignment median ropes in the Dome Valley. This used to be a “normal” undivided highway.
The modern motorway sections are so expensive that much can be done with far less budget.
An Example Project
When we talk about all these ideas it's useful to use real world examples. One such project is the Dome Valley safety improvements, to the north of Auckland on State Highway 1. It’s not a perfect project, but it's a good example of what can be done.
This was funded as a part of Waka Kotahi’s Road to Zero program at a cost of $67 million, and is currently sitting at a Benefit to Cost Ratio (BCR) of 1.4. The project treatment area is 12km of mostly winding, steep terrain, with ‘complex geotechnical conditions’, on a road that has to remain open throughout the works. In most ways it’s a worst case scenario for this kind of road building. It was an extremely dangerous section of state highway. Waka Kotahi estimates these Dome Valley improvements will bring a 68% reduction in Death and Serious Injury (DSI) on this stretch. Elsewhere Waka Kotahi claims that with median and roadside barriers the reduction can be up to 90%.
The works involve adding median wire ropes, paved shoulders, turning bays for side roads and U-turn facilities, adding more side crash barriers, and putting in hard shoulders so broken down cars or tractors can be passed. All this has necessitated meters more carriageway width, created by hundreds of metres of retaining walls and embankment. This is not cherry picking, it is by no means a cheap or straightforward example.
All of this works out to 5.6 million per km. If it can be done here, then it can be done on almost all of the state highway network.
This project also goes a long way to solving resilience issues. A source of a lot of closure hours on these state highway sections are crash cleanups. Getting a helicopter or ambulance in, police investigations, firefighters extracting people. These closure hours are shortened when crashes are less severe. A lot of geotech work is also being done, although there is evidently more needed. You can solve a lot of potential problems for a lot less money than an expressway section.
Giving Meaning to Costs
The upper projected cost of the Warkworth to Wellsford motorway, in 2019 (would certainly be higher now) was 2.1 billion dollars. If this money were instead used on the same treatment model as Dome Valley, for the same price per km of around 5.6 million, we could treat from Warkworth to the northernmost extent of SH1 at Cape Reinga. 360 km of road, and still get some change out of it. Or if you’re of the south island persuasion, treat from Christchurch to Dunedin.
Now this is clearly an oversimplification, but the enormous distances you can treat, and the safety you can buy is obvious. A 60-90% reduction in DSI over 360km of road is clearly going to be a much bigger saving than even a (pretend) 100% reduction over 50km. Especially if we targeted the most dangerous % of state highways. We have a certain amount of money, we should choose to spend it in the most efficient way. To buy as much safety and resilience as we can.
Not only will the number of lives saved be far higher with such a funding reallocation, but the long term economic returns are better too. Like I mentioned above, these upgrade projects actually can have a positive BCR (ie make a net economic contribution), while being affordable enough to quickly bring to a huge portion of the State Highway network. The social benefits from killing significantly less people are untold.
Resilience
I had initially written this all about safety, but the same logic applies to resilience improvements. As a result of Cyclone Gabrielle and the upper north island flooding there has been widespread road damage and closures.
Unfortunately we have been seeing some politicians (and hangers on) saying that we need to build even more 4 lane expressways, and that clearly the problem at the moment is we just didn’t build enough expressways in their chosen area. This is either delusion, or worse, purposeful politicisation of a crisis which will make future crises worse.
Firstly, it is funny that people associate 4 lanes with resilience. As if flood waters think “ohhh naaa, that one's got 4 lanes not 2, better go around”. This association has come about purely because the only rural highways that are up to a decent safety and geotechnical standard happen to be 4 lanes. Capacity has come before resilience or safety, and sucked funding out of critical highways that happen to have spare capacity, resulting in these poor outcomes.
It is absolutely impossible to build enough 4 lane expressways to buy road security for most of regional NZ with our current population. For example, to build a 4 lane expressway from Warkworth to Whangarei alone, we’re talking about spending money on the order of the entire yearly GDP of the Northland Region. And that wouldn’t solve many issues for anyone that happens to live any meaningful distance from this proverbial highway. You get a handful of major population centres connected, while everyone else is hung out to dry. This is not an equitable solution.
We are a disaster prone country. Everywhere is vulnerable in some way or another. And it is getting worse. The widespread solutions cannot cost 60+ million dollars per km like some contemporary expressways do. Improvements need to be spread across the entire network and be affordable enough to actually happen. They need to be targeted to the most (economically) damaging problems, safety and resilience. And be efficient at solving them.
In almost all cases there are cheaper, faster fixes to buy infrastructure resilience. Building retaining walls, soil nailing, upgrading drainage, bridge strengthening or renewals. Or even building new bypass sections, but just with 2 lanes instead of 4, to a more cost conscious alignment standard. These kinds of projects are all too rarely undertaken, or even proposed because so much capex has been directed towards the 3 hot expressway corridors around Auckland and Wellington.
Even Steven Joyce’s old fever-dream expressway scheme only covers a few bases. And with contemporary expressway pricing of around 60 million per km or more, would cost on the order of 50 Billion dollars. Mostly on highways that simply don’t have enough demand to justify 4 lanes.
Capacity First
Throughout all of this, one core thing has remained unsaid. The positives of capacity. This has been at the centre of why Waka Kotahi and politicians don't see these safety / resilience only options as being great in the past. What good is highway spending if the median voter driver still has to sit in traffic on long weekends? or still feels discomfort while doing 30 over the recommended corner speed? Or you don’t get a career highlight project out of it.
More people having better transport is good. But capacity must pay for itself. Spending a dollar to buy 30 cents of return from additional capacity is totally unjustifiable.
Resilience and Safety are the headline marketing items on expressway projects. But knowing we have better alternatives exist, these expressways are in a way anti-safety. We are choosing to spend money in a way that results in more people dying in total than an alternative program.
The End
Not to end on a downer. The fact we actually have viable paths towards solving the worst of our rural highway issues is great! Please, make arguments for realistic road upgrades in your area. If you’re an advocate or politician representing a rural or smaller regional area, know that these upgrade options exist. Know that they are a massive improvement to safety and could be huge for resilience. If you succeed there will be people walking around your community in the future that would have been killed otherwise. And future closure hours (or days) avoided.
We will have a much better shot of getting meaningful improvements in people’s lives soon by asking for funding for ropes, better intersections, and collections of smaller upgrades.
Great post. It puts into words what seemed clear to me in Wellington decades ago with transmission gully, it could have been built first as 2 lane and the seaward route used to manage capacity, but no we had to wait a few decades for the 4 lane version.
Rimutaka hill road should be next but I bet they’re thinking it needs to be 4 lane at the get go so will be more decades