This is a guest post by Greater Auckland reader Jack Gibbons.
Beginning tomorrow, July 13th, the Waikato Expressway from Hampton Downs to Cambridge will have the speed limit of 110km/hr.
Today, July 12th, there is going to be an opening ceremony for the Hamilton section of the expressway. When this section opens it will fill in the gap and the expressway will run continuously from the Bombays to Cambridge.
At the time of writing, the section from Cambridge to Tamahere is open and is set at 110km/hr, and the sections from Hampton Downs to Ngāruawāhia are open and set at 100km/hr. North of Hampton Downs the quality of the infra declines significantly, with a number of dangerous at-grade intersections. There are no plans to upgrade that section yet.
As a preface: I don’t want to give the impression that the expressway or this speed limit raising is purely (or even mostly) negative. I like the option to drive faster, I appreciate the engineering effort that has gone into the expressway, and will enjoy just how easy this drive has been made.
This post is specifically talking about the speed limit on the highway, not the highway itself. For some reason there are a lot of parties conflating the two together (here’s an example). The limit raising has to stand on its own merits independently of the new highway.
The obvious benefit of the higher speed limit is the time savings. The hypothetical time difference between a 100km/hr limit and 110km/hr, assuming a vehicle could stay at the limit for the whole stretch of road (78km), is 4 minutes 15 seconds.
It is important to consider that this saving won’t be realised for a good subset of trips. For example, congestion can still occur. More importantly, heavy vehicles, buses, and light vehicles towing trailers are (appropriately) all still limited to 90km/hr. This means that any travel time savings are only available for private cars, utes and vans.
The raising of the limit will increase fuel consumption on this corridor (per km travelled), and decrease vehicle fuel efficiency.
Waka Kotahi have been quoted saying that the extra 10km/hr will add 4.34% of per km CO2 emissions directly (citation) on the corridor at a date picked in 2031.
They have not (that I have been able to find) released the full environmental impact study, and this one data point obscures a lot. For example:
- That 4.34% number is taken in 2031 and will assume growth in EV makeup in the fleet before then. The difference between the two limits is likely higher in the years before 2031.
- This number also ignores induced demand, and land use changes from the shorter trip times, which will play a part in time.
- This figure measures total corridor emissions but all heavy traffic is limited to 90km/hr in both scenarios. As such the increase in emissions is solely coming from the light vehicle fleet, the percentage increase for the light fleet must be higher.
According to Waka Kotahi’s modelling and fleet statistics, the most CO2 efficient speed (per km travelled) for the NZ light vehicle fleet is around 70-75km/hr, with the efficiency getting worse at higher speeds. There are of course variations with different vehicles, road and weather conditions etc, but generally there isn’t a circumstance where it is more efficient to drive 10km/hr faster at 110.
Now, this carbon is priced in the ETS, so a portion of the fuel price goes into paying for CO2 emissions. However I don’t think this is quite good enough. Fuel prices are heavily politicised and fuel is subject to market interventions if prices rise enough (as we’ve seen). It’s likely that carbon prices will have to rise a lot if we are to meet international agreements. Given that, raising fuel consumption, and therefore raising the public’s exposure to carbon prices is undesirable. Under the ETS intent today there should be no net increase in emissions from this limit change, but that might not always be the case.
I also argue that the price / speed tradeoff is a very opaque one that the general public is unlikely to make rationally because:
- There is still significant social pressure to do the speed limit on the expressway, and animosity to drivers that are doing well under the limit, even in the left lane. (this should be fixed)
- It is extremely difficult to determine the price difference between a trip done at two different speeds. People can’t be expected to make the mental calculation about whether the cost tradeoff is worth the time, without knowing the price.
As it stands today I speculate that most people will do the limit, not realise the alternative, not take account the price signals, and this will then increase the (ETS breaking) political strife when the chickens come home to roost.
CO2 is not the only output that will increase. Last week a study was published that squarely points the finger at NO2 produced by motor vehicles as a huge health concern for the country. Higher speeds will cause an increase in NO2 production from light diesels. How much is up for debate, the NZTA have not published all of the modelling for the higher limit yet (at least from what I can find).
Parts of the alignment pass close to population centres, in particular Hamilton and Cambridge, with rapidly expanding suburbs, and a school with over 2000 students already built right next to the expressway where there will be a negative impact.
Safety for vehicles.
To meet the standards required for 110km/hr operations, there have had to be some barrier, shoulder, and surfacing upgrades to the earlier parts of the expressway, and the most recent sections have been built suitable for 110km/hr from opening.
The increase in speed will have negative safety implications for people in vehicles, adding more energy to any incident has to have some influence. However this section of road is very safe for those in vehicles. It has full grade separation, controlled access, perfect superelevation, long sightlines, full barrier protection on both sides from the safest barrier type deployed in NZ. Under normal operation there is no chance of side impacts or head on collisions. It is consistent with vision zero in general, for roads like this to operate at speeds over 100km/hr. There isn’t anything wrong with driving fast on good infrastructure in good conditions.
There is unfortunately a giant red flag exception in the Waikato Expressway’s case.
Active modes safety
With the loose “expressway” designation, people are allowed to walk and bike on the shoulder of the highway. Waka Kotahi even painted these at-grade bike crossings on some of the off-ramps.
In the first place, how was this multi-billion dollar corridor, connecting the largest city in the country and its neighbour, almost 2 million people combined, built without a simple offline walking / biking path?
The corridor having enough demand to justify a full expressway, around 20,000 vehicles per day, is clearly an indication of its importance.
In my opinion, there is a moral obligation to provide some guaranteed minimal level of mobility, especially on such an important corridor. If you don’t have much money, if you don’t have a full or restricted car licence (which 30% of the country doesn’t), if you do have a licence but are unable to drive, if you don’t have access to a car, or means to buy one… There still needs to be some guaranteed way (no matter how inconvenient) of safely getting yourself from A to B. The best way to meet this need would be with an offline shared path that partially follows the expressway alignment.
While people outside of a vehicle are extremely likely to be killed by being hit at both 100km/hr and 110km/hr, the added 10km/hr will decrease reaction times, and will increase stopping distances. It is not consistent with vision zero to raise the limit, just as it wasn’t to build brand-new expressway sections while providing inherently unsafe active modes infrastructure.
Fixing active modes safety
One of the requirements for expressways should be no non-motorised traffic allowed. It is not a safe system to allow bikes or pedestrians inside the crash barriers on the shoulder of an expressway.
But we can’t just kick active modes off the existing expressway with no replacement. Even Waka Kotahi recognises that, saying: “Generally the 110km/h expressways will be safer for cyclists than negotiating the adjoining local road network” (quite the indictment of the rest of the road network). The expressway being the safest route – despite the extreme danger it presents to cyclists – is exactly why there’ll be very few cyclists at all, and why the likely very low use of the expressway by bikes shouldn’t be a reason for not providing safety. There is again a moral obligation to not make walking and biking even more dangerous.
We should retrofit this corridor with a separated offline path. A lot of the alignment already has spare room beside it within the existing right-of-way. There are also a number of service roads that have been built to connect properties previously served directly by SH1. These could have speed limits lowered and form sections of the path. Sensible deviations away from the noise of the highway would also enhance the quality of a walking and cycling path.
Waka Kotahi are already actually doing a little bit of active modes building with a pedestrian path on a 6km stretch of the expressway near Meremere, to provide a route for walkers of the Te Araroa trail and get them off the expressway shoulder.
The speed limit raising was consulted on last year. To me it’s a fairly poor example of consultation, and is not really used appropriately in the media. Consultations are not a form of direct democracy and are not intended to be. Lines in articles like: “…with only 10 opposing on climate change grounds…” are very leading and imply that the results are a vote amongst a group to determine the outcome of a proposal. This is not the purpose of consultation.
The project page(s) on the 110km/hr limits (linked here and here) are very sparse on the research and documentation about environmental impacts. The public were given very little information to make a meaningful contribution. How many more people would have shown concerns about Waka Kotahi choosing to raise emissions on this corridor if the agency were more upfront with the fact that they are?
Some people did raise climate concerns, most of which were thoughtful, informed responses. There is a Consultation Summary with a section where concerns brought up by the public are addressed. Waka Kotahi makes no mention of climate, emissions, or active mode safety here.
A better option for limit raising?
I also can’t help but think there was a missed opportunity to at least promote EVs or low(er) emissions vehicles here. Instead of giving every light vehicle the 110km/hr limit, vehicles that emit under a certain amount of CO2 or NOx per km could have been given the go-ahead. While a 4 minute time saving on what is likely an occasional regional trip doesn’t seem like much incentive, I think this would have an outsized effect on EV and low emissions vehicle uptake. It gives people more reasons to buy efficient / cleaner vehicles, and solves the opaque vehicle efficiency problem like it’s traditionally been solved, at time of vehicle purchase.
Raising the speed limit on the Waikato Expressway as it stands is a retrograde step. Accommodating cycling so poorly into the design is not safe, nor remotely consistent with Vision Zero. The increased speed limit has also created extra emissions and health downsides that were unnecessary. There were ways they could have mitigated these downsides. I can’t help but see the missed opportunities here, and hope future transport projects will not have the same flaws.
If Waka Kotahi takes the Road to Zero strategy seriously, this corridor will need to be urgently retrofitted with a safe, separated and protected active modes path.