Traffic Preserves

Just before Christmas, Auckland Transport released this cute video about the causes of congestion and how to help avoid it,

The press release focused on the holiday period but I can also see them using this campaign later in the year, especially in February and March as the roads get busier.

Congestion on our motorways is frustrating at any time of year, but during the busy holiday season it can be worse than ever.

Auckland Transport’s ‘Spread the jam’ video has been produced to simply explain how traffic congestion can start.

AT’s chief transport operations officer, Andrew Allen, says there are generally four causes of congestion. “Usually it’s drivers cutting-in, following too close to the vehicle in front, rubber-necking or being distracted like using their cell phone. A heavy dab on the brakes can cause a ripple effect right down the motorway turning free flowing traffic into a sticky jam!

“All drivers have to do is always maintain their following distance and give plenty of warning before changing lanes, so use your indicators.”

He says if people are more aware of the causes of traffic congestion and modify their own behaviour our motorways will run more smoothly.

Barney Irvine from the Automobile Association says the answer lies with motorists. “Driver behaviour makes a bad congestion situation even worse – AA members recognise it, and they want to see more done to raise awareness. ‘Spread the jam’ is definitely a step in the right direction, and we’re right behind it.”

A study in 2014 found that the annual cost of congestion in Auckland was $1.25 billion when compared with free-flow traffic conditions.

Remember, spread the jam:

  • Keep your following distance.
  • Don’t cut in.
  • Don’t rubberneck.
  • Avoid distractions like cell phones.

As cute as the video is, and it’s a decent start, there’s a couple things I wanted to point out.

  1. The primary cause of congestion is of course, too many vehicles on the road at the same time. Although getting people to drive better is certainly a good thing, especially on urban streets where more vulnerable road users (pedestrians and bikes) are around.
  2. Another way to spread the jam is to simply not participate in it. This can mean travelling at different times or by other modes, particularly those that aren’t affected by congestion such as the Northern Busway, rail network or bus routes with good levels of bus priority. This is obviously a bit harder on holiday trips like the press release was focused on but for regular commutes it may be a viable option.
  3. It is interesting that AT specifically mention the cost of congestion being $1.25 billion compared to free flow. The emphasis is important as the study (for the NZTA) that came up with that figure (actually from 2013) suggested that based on optimising the network capacity, the cost was only $250 million, considerably less. That’s because it absurd to build any transport network to be completely uncongested at all times of the day – in the absence of pricing. Particularly with roads, the financial cost of doing so would be astronomical, not to mention just how much land would be needed.


Overall a useful message but to me it’s just one part of the congestion equation.

Slowest City tag meaningless

The media seem went gaga a few days ago about a new report that looks at the impacts of congestion in Auckland and other Australasian cities. It’s no surprise they reported on it either, transport in Auckland is a common gripe and so the story of Auckland being the slowest city, confirming what many people already believe, was too much to pass up.

But even reading the news articles, it struck me that this was likely another case of the wrong questions being asked but that by in large, the right answers were reached, much like ATAP. Perhaps even more so it wasn’t the main findings of the report that were important but some of the ancillary comments.

The report is by Austroads, a key organisation in the development of road networks in Australasia. Here’s some of what the Herald said about it.

Auckland commuters can groan in agreement with a report that reveals the city has the worst travel times and reliability in Australia and New Zealand.

This is despite having the fastest road in the two countries combined.

Austroads Congestion and Reliability Review measured the levels of congestion and traffic across major cities in Australia and New Zealand and released their findings in a report.

The cities were categorised into groups of similar population size. Auckland was in group two alongside Perth, Brisbane and Adelaide.

In its group Auckland performed worst across “most measures”. These included the highest travel time delay, morning and afternoon peak reliability.

Auckland came out worst in it’s group with an average speed of 77.6km/hr. The other cities were between 82km/hr to 86km/hr. American cities of a comparative size went up to 104km/hr.

The slowest roads were St Lukes Rd, Wairau Rd and Lake Rd. While the fastest were the Northern Gateway Toll Rd (which topped the Australasian list with an average speed of 98.8km/hr), Upper Harbour Motorway and SH16.

By focusing on the speed of commutes, my immediate feeling was that this sounds like a very similar approach taken by Tom Tom and other organisations for their own congestion reports. This proved to be correct as this is what the press release says about the method they used.

The findings are based on an analysis of Google Maps data for 600km of roads for each major Australian city, enabling analysis of travel time along different road segments. The analysis was based on two months of data, comprising of 1km long road segments, with data points taken every 15 minutes, to calculate the six key congestion measures outlined in the report. An econometric analysis was then undertaken to provide insight into the drivers of network performance.

We’ve written before about TomTom’s reports, one of the key problems with reports that use this kind of methodology are that they are based on measuring the variance in the speed of traffic compared to the maximum speed limit allowed on the road. This ignores that roads can be more efficient and flow better with lower speeds, for example a motorway will move more vehicles an hour/flow better if they’re all travelling at 80km/h than 100km/h.

Also importantly, these reports only ever reference vehicle congestion/speeds, not the people using that corridor. Infrastructure like the rail network and Northern Busway allow a lot more people to be moved within a corridor, often faster and free of congestion. We know that 40% of people crossing the Harbour Bridge every morning on a comparatively small number of buses don’t suffer from the congestion those in cars next to them have endured.

But it’s here were we reach one of those right answer to the wrong question points. That’s because while we know that counting the speed of PT and other road users is key if we want a more accurate report, we also know that Auckland is one of the worst performers when it comes to use of other modes, something noted by the authors when they say

Auckland has fewer public transport options, compared with other cities. Plentiful low-cost parking in Auckland encourages commuters to drive.

Looking at the articles also raised a new potential issue with how these kinds of congestion metrics are created, in particular the mention that the Northern Gateway Toll Road was the fastest in Australasia. In short, why would you count a rural tolled motorway. Other than on holiday weekends, which wouldn’t be relevant in this discussion, this road has almost no bearing on the congestion most Aucklanders might experience. But that got me thinking, if the toll road is included in Auckland’s numbers, what else is included, especially in other cities.

So here’s Auckland’s map of the most delayed roads based on their methodology.

And as one example, here’s Perth which comes out much better in the metrics.

And Brisbane

One thing worth noting is it appears these maps are not at the same scale, the furthermost point away from the Auckland City Centre is about Drury, 30km away. By comparison in Brisbane and Perth some of the locations shown are over 50km away from the city centre. This hints at one of the potential issues, there are a lot more uncongested rural highways included in the numbers of other cities compared to Auckland. To be fair, in the middle of the report they do say that the types of roads selected for this report will impact the results i.e. more motorways generally results in higher average speeds.

The report also looks at some international cities as comparisons but oddly they decided specifically to choose cites with similar PT modeshares to the Australasian cities which means cities of similar sizes and densities in places like Europe and North America can’t be compared to see if there’s something cities here could learn if there was a different transport/land use focus.

As mentioned earlier though, despite issues with some of the ways this report has been approached, I do think it comes up with some useful points.

More important that the speed of a particular journey is the reliability of it. If you know it’s always going to be slow then at least you can accept that, or adjust when or how you travel to avoid it. But when that varies considerably every day it can be infuriating. Of course, Auckland fares poorly in the reliability rankings

They also make some very salient points about why Auckland performs poorly. These include:

  • Auckland’s geography, particularly its harbours and waterways, impose constraints on the transport system, meaning the main transport links are confined to narrow corridors
  • Compared with other cities there is a lower level of public transport provision for commuters
  • There exists highly available and low cost parking in Auckland which encourages commuters to drive

Auckland’s geographic constraints forces a lot of people to travel through narrow areas, if only there was a way to move a lot of people without needing a lot of space to do so. Despite what some urban myths would have you believe, that makes Auckland ideally suited to public transport, if was provided it well. This is something backed up to some degree by ATAP, which noted that there are only limited options for expanding road capacity within most of the urban area.

There is no one solution to ‘solve’ congestion but definitely a “more of the same but bigger” approach will not work. If Auckland wants a chance of improving congestion it will need provide better alternatives so the best option isn’t to sit in a car and hope for the best.

Airport Anarchy

For years, we and many others have been saying that better options are needed for accessing the airport and for even longer, politicians, officials and experts have either wilfully ignored the need to serve one of Auckland’s major destinations with public transport or have actively opposed and sabotaged it. Now the chickens are coming home to roost with roads reportedly clogged so bad that many are missing flights or commenting that it took longer to drive home from the airport than fly to Auckland from Sydney. It seems even Mayor Phil Goff got caught in the mayhem. And things could get worse with the airports busiest days of the year coming up.

The transport planners from the NZTA have pinned their hopes on upgrading the motorway to the airport by grade separating Kirkbride Rd – due to be completed next year some time – but one of the major problems with it is that while it removes an intersection, it doesn’t really add any extra capacity to the road network so going to do bugger all to solve congestion within the airport itself. There are of course some bus options but they suffer from the same congestion as cars.

To really have a chance of making a difference in getting to the airport, we need good alternatives. Perhaps one of the issues we’ve had is that almost all of the discussion is focused on long term solutions, currently expected to be light rail (we don’t need another debate about rail mode in this post thanks). Yet despite this route being a major issue for Aucklanders, in the six years since Auckland was amalgamated, almost nothing has been done to protect the route and ATAP doesn’t suggest anything will be build (from the north) till after 2026. That’s simply too far away.


One of the reasons things have come to a head so rapidly has been due to a surge in airport usage. In the 12 months to the end of October, 17.3 million people passed through the airport (domestic and international), an impressive increase of 11% over October 2015.

Essentially it appears that a tipping point has been reached where growth at the airport, along with the heavily auto-dependent development around it, have combined to cause chaos. It now appears to have caused enough embarrassment that authorities are pretending to do something about it.

Transport authorities and Auckland Airport have set up a taskforce to tackle traffic chaos that has led to some passengers missing flights.

The NZ Transport Agency, Auckland Transport and the airport company have established a group to find immediate ways to improve travel times and congestion on the roads and state highways to, from and around Auckland Airport.

Of course, what’s proposed is mostly nothing more that tinkering around the edges.

The taskforce had agreed to accelerate a number of planned initiatives, including:

  • changes to lane configurations at the State Highway 20B (Puhinui Rd) / State Highway 20 interchange before Christmas to increase traffic flows through the intersection;
  • the Auckland Transport Operations Centre will optimise traffic signals to increase traffic flows at peak times on the state highways and airport roads, and publish additional airport-specific travel time information;
  • changes to lane configurations on George Bolt Memorial Drive / Tom Pearce Drive to improve traffic flows to both airport terminals;
  • changes to lane configurations on George Bolt Memorial Drive / Laurence Stevens Drive roundabout to improve traffic flows to the domestic terminal; and
  • deploying special temporary traffic management plans on Auckland Airport’s roads to increase the network’s resilience.

The immediate solutions are in addition to the major improvements already underway to deliver additional network capacity and improve travel times, including:

  • the $140 million upgrade of State Highway 20A and improvements to the State Highway 20A / Kirkbride Road interchange which will create significant extra capacity;
  • the upgrade of the George Bolt Memorial Drive / The Landing Drive / Verissimo Drive intersection; and
  • new bus lanes heading towards the airport on State Highway 20A.

So here are my views on solutions that need to take place.

Long Term – and that needs to happen within the next decade, not remain over a decade away like ATAP suggests, a dedicated Rapid Transit line is needed. As mentioned earlier that is currently planned to be light rail but the government and their agencies are trying to get that downgraded to just a bus connection.

Medium Term – As Patrick pointed out in this post, a quick first stem to getting an RTN style connection to the airport would be to build a busway connecting the Puhinui Train Stations with the airport. This would require a busway alongside Puhinui Rd (SH20B).

Short Term – Here are a few thoughts on some short-term options.

  • Skybus – Skybus operate services to the city with fares of $18. Unfortunately, like cars these buses also gets caught in congestion on the motorway. Further I’ve seen a number of comments in months that the quality of the service has been decreasing. Perhaps Skybus could be encouraged to run more services and with AT/NZTA covering some of the costs.
  • The 380 option – The 380 bus runs from Manukau to the airport via the Papatoetoe Train station which can have trains stopping in each direction to/from Britomart every 5-minutes. This could be a great option but it currently suffers from a few issues.
    • AT don’t market this option very much so many people don’t know it even exists – this could be easily fixed.
    • Last I heard, transferring between the train and bus wasn’t well advertised or signposted – this could be easily fixed
    • Unfortunately the congestion referred to above affects both SH20A and SH20B. With no bus lanes on the latter it means the bus gets caught in the same congestion as the cars.
    • The service is nowhere near frequent enough, only running every half hour during the day and this is an issue that we shouldn’t even have. Back when AT announced the result of consultation on the new bus network that has just rolled out in South Auckland, the ’30’ bus (a new name for the 380) was listed as one of the frequent services that would see a bus running at a minimum of every 15 minutes, 7am-7pm, 7-days a week (as shown below). Yet after AT finished tendering for services this was dropped back to a secondary route running only every 30 minutes, despite AT crowing about saving money. As such, as a first step they should implement the new network as they told the community it would be and improve the frequency of this service back to frequent status.
      • The article says this: “Auckland Transport’s chief executive, David Warburton said AT would continue to focus on how it can increase public transport services to and from the airport “. So I’m sure David will be announcing improved services soon?




  • Interim priority lanes – If the NZTA were really serious about improving options, perhaps they could dedicate one of the motorway lanes to high capacity vehicles. This would obviously include buses but could also include other vehicles with a lot of occupants, perhaps T4 and above.
  • Park n Ride – Even if the NTZA got underway now with their plans to widen SH20B, it would be years before that work was finished. We don’t normally advocate for Park n Ride but perhaps in this situation, one along Puhinui Rd, near the whereas it could be justified along with a shuttle – or ideally a much more frequent 380 bus.

Those are just a few thoughts, what do you think should be done to make some quick wins?

The Ideology of Traffic

Sometimes we come across something that is so perfect and so timely that it just needs repeating as it is. This is one of those times. The following post by Charles Marohn is lifted in its entirety from


The Ideology of Traffic by Charles Marohn

The greatest accomplishment of any ideology is to not be considered an ideology; to be a belief system that is not considered a belief system. Millions of Americans went to church yesterday and every one of them knew their experience constituted a belief, that others in the world believe other things. It is when beliefs are not recognized as such that things get scary.

“This approach to design – speed then volume then safety then cost – reflects the ideology of the profession, an internal belief system so foundational that they don’t recognize it as the application of a set of values.”

Last week I was in Washington State speaking to a group of mostly transportation engineers and technical professionals. My presentation was all about questioning the core beliefs of the profession, of helping the people in attendance recognize that many of their core truths are actually beliefs, and that there are competing beliefs that they should consider.

For example, when engineers design a street, they begin with the design speed. They then determine the projected traffic volume. Given speed and volume, they then look to a design manual to determine the safe street section and then, once a cross section is selected, determine the cost. This approach to design – speed then volume then safety then cost – reflects the ideology of the profession, an internal belief system so foundational that they don’t recognize it as the application of a set of values.

Of course, when presented with these values discretely and not as part of a design process – not as part of the ritual practice of their belief system – they collectively identified a different set of values. I actually had them shout out their values in order and, like the thousands of people I’ve asked to do the same, theirs came back: safety first, then cost then volume and, last, speed. Their actual values are nearly a perfect inversion of those they apply to their design ritual.

This weekend, there was an article that appeared in the NY Post titled The Real Reason for New York City’s Traffic Nightmare. I know the Post is tabloidy; the story contained all anonymous sources and lacked even a rudimentary level of fact checking that you’d find in an actual news story. Still, it fits the ideology of the traffic engineering profession and I saw the piece widely distributed. Here’s a quote:

“The traffic is being engineered,” a former top NYPD official told The Post, explaining a long-term plan that began under Mayor Mike Bloomberg and hasn’t slowed with Mayor de Blasio.

“The city streets are being engineered to create traffic congestion, to slow traffic down, to favor bikers and pedestrians,” the former official said.

“There’s a reduction in capacity through the introduction of bike lanes and streets and lanes being closed down.”

Let’s apply a contrasting value system to this quote, not one based on moving traffic but one based on building wealth. Here’s how each of these statements could be rewritten:

Ideology of Traffic: The city streets are being engineered to create traffic congestion.
Ideology of Wealth Creation: The city streets are being engineered to make property more valuable, encourage investment and improve the city’s tax base while reducing its overall costs.

Ideology of Traffic: The city streets are being engineered to slow traffic.
Ideology of Wealth Creation: The city streets are being engineered to improve the quality of the space for the people who live, work and own property there.

Ideology of Traffic: The city streets are being engineered to favor bikers and pedestrians.
Ideology of Wealth Creation: The city streets are being engineered to favor the access of high volumes of people over the movement of comparatively small volumes of automobiles.

Ideology of Traffic: There’s a reduction in capacity through the introduction of bike lanes and streets and lanes being closed down.
Ideology of Wealth Creation: There’s an improvement in the quality of the place and it’s corresponding value through the introduction of bike lanes and the closing of some streets and lanes.

Before the Suburban Experiment, cities were built with an ideology of wealth creation. That ideology was shared across the culture and, while some benefitted more than others, it provided opportunity for nearly everyone to get ahead. To understand why our cities are going broke, why they are struggling in a growing economy just to do basic things, one only needs to consider the dramatics of this ideological shift. We’ll bankrupt ourselves moving traffic and we don’t even understand why.

Time to adopt a Strong Towns mindset.

A vision for the future, from LA

The I-405 is one of Los Angeles biggest and busiest freeways and just a few years ago underwent a US$1 billion widening project. But as the saying goes, what you feed grows and a few days ago that was highlighted in nightmarish fashion as tens of thousands tried to get away for Thanksgiving. The images come from ABC7 Eyewitness News twitter feed. All modes can have issues from time to time but unless we can focus on developing some serious multi-modal options then perhaps this will be a vision of Auckland’s future.


And is if that isn’t bad enough, here’s a video of it showing the traffic extending a long way

And one more shot of it

Congestion in large Australasian cities

Is Auckland abnormally congested?

I occasionally hear people bemoaning that Auckland is one of the most congested cities in the world, or at least one of the most congested cities for its size.

I’ve previously taken a look at this from a few angles – looking at trends in traffic delay in Auckland and average commuting time in large cities around the world. Auckland looks pretty good on the latter measure, which kind of belies the “most congested city” rhetoric:

Avg commute times in large cities

For another look at the same issue, we can take a look at data on traffic delay in cities across New Zealand and Australia.

Helpfully, the Australian Bureau of Infrastructure, Transport and Regional Economics (BITRE) publishes data on the cost of congestion in large Australian cities. They measure congestion as the amount of traffic delay that could feasibly be avoided without reducing the overall value that people get out of travelling.

Unfortunately, comparable figures aren’t available for New Zealand cities. The Ministry of Transport tracks delays in traffic, but doesn’t make monetised estimates of avoidable congestion costs. However, it isn’t that hard to make a reasonable estimate, if you combine MoT’s traffic delay statistics (average delay of 0.52 minutes per kilometre in March 2014, but less in the November survey) with their data on the total amount of vehicle travel in Auckland (12.7 billion vehicle-kilometres driven in 2014).

Following BITRE’s approach, I’ve assumed that avoidable congestion is about 55% of total delay – reflecting the fact that many people prefer to travel even on congested roads. I then monetised the total delay-hours using NZTA’s standard figures for the value of travel time (around $23.40 in 2015 dollars) and converted between Australian and New Zealand money. After mixing in some data on city population in Australia and New Zealand, I got the following chart:

Aus NZ city population congestion costs chart

Each individual point is an observation from a single city in a single year – so it’s possible to see how congestion has evolved over time in each city. We can immediately see three important things from this chart.

The first is that Auckland is right on the trend-line. We have the congestion levels that you’d expect to see in an Australasian city with 1.5 million residents – right between Adelaide and Perth. So once again, there are no signs that Auckland is particularly exceptional in the traffic congestion area.

The second is that congestion is a nonlinear phenomenon – it increases faster than city size. You can see that in the upward-sloping trendline fitted through the points on the graph. On average, in this sample of cities, a 10% increase in population is associated with around a 13% increase in congestion levels.

What that means is that new residents entering the city experience the average congestion levels in the city – 10% of that 13% increase – and also have a (relatively small) negative impact on congestion for existing residents – the remaining 3% increase.

The third is that, setting aside the average relationships across all of the cities, individual cities appear to follow slightly different trends. For instance, while Perth and Melbourne have followed the trend-line pretty closely, there seems to be a steeper relationship between congestion and population size in Adelaide and Brisbane.

That suggests that urban policies – land use, transport investments, etc – can enable some cities to grow in more or less efficient ways. Which specific urban policies are better or worse is a bit of a vexing question – but there does appear to be something there.

What do you make of the data on congestion costs in Australasian cities?

What are the preconditions for congestion pricing in Auckland?

The inclusion of congestion pricing in the recent Auckland Transport Alignment Project interim report has (helpfully) reignited the public debate on the topic. Transportblog’s authors have been pretty enthusiastic about the idea – see e.g. Stu Donovan’s posts on the topic.

But the announcement also raises some questions. For example, congestion pricing is certainly a good idea in principle, but could we put it into practice in Auckland without unintended consequences? And would people in Auckland get on board with it?

So I thought I’d open this up to readers: What do you think the preconditions are for congestion pricing in Auckland? In other words, what would we have to do in order to make the scheme work?

I have my own thoughts on the matter, but rather than putting them forward I thought I’d summarise some of the main things that come up in discussions. I’ve left aside the exact design and technical feasibility of congestion pricing – for now, let’s just assume that it’s going to be possible to implement a GPS-based pricing system that allows for variable tolls between different roads and time periods.

1. We don’t need to do anything else.

Some people argue that congestion pricing will work without any further changes to transport infrastructure or services. Stu, for example, put forward this case the other week.

The argument in favour of this view is that congestion is typically very concentrated in peak periods due to bottleneck delay, and that encouraging people to take some trips a bit earlier or a bit later will benefit the overall transport network without imposing large costs on people who re-time journeys to avoid tolls.

2. We need to provide more public transport infrastructure and/or walking and cycling options before implementing congestion pricing.

A second common view is that we need alternative, non-driving transport options in place prior to congestion pricing. Reasonable people could disagree on what would represent enough alternatives, but I’d suggest that a reasonable aspiration would be:

  • Bus routes that cover most of the city, with reasonable frequency
  • Spare rapid transit capacity through key pinch points such as the Auckland Harbour Bridge and Panmure Bridge
  • Cycle lanes running on or parallel to many urban arterials.

The argument in favour of this view is that it is unfair to ask people to pay a toll without giving them options for avoiding it. In that respect, it conflicts a bit with the first view, which holds that people will have the option of re-timing trips to avoid tolls.

3. We need to use the revenue from congestion pricing to improve transport infrastructure and services on busy corridors.

A third view is that we should spend any additional revenues from congestion pricing to build additional transport infrastructure. Some people argue that this should be more roads, while others argue for public transport.

It seems a bit perverse to implement a demand management measure (congestion pricing) and then turn around and spend more building infrastructure. However, the argument in favour of this view is that congestion pricing will give us a better indication of which corridors have high economic value – as evidenced by higher tolls – and hence that investment is needed to allow more people to use them.

4. We should “recycle” additional revenue from congestion pricing into lower taxes or rates.

Another view on what to do with the revenue from congestion pricing is that it should be returned to households. In other words, the scheme should be “revenue neutral” on the whole.

There are two main ways to do this:

  • Lowering income taxes, which will (all else equal) enhance incentives to work while discouraging car commuting at peak times
  • Distributing money equally to households, through lower uniform charges in the rates bill or AECT-style dividends.

The argument in favour of the first approach is that it will tax “bads” (i.e. excess congestion) while rewarding the “goods” (i.e. working). The second approach doesn’t improve incentives to work – people would get the money regardless of whether they are working or not – but it would ensure that every household had an additional chunk of money that they could choose to save, spend, or use to offset the cost of tolls.

5. We should liberalise residential and business zoning rules alongside implementing congestion pricing.

Separate from what to do with the revenues, another view is that it would be necessary to change our approach to land use planning in order to get the best result from congestion pricing.

The argument in favour of this view is that congestion pricing would influence people’s decisions about where to live and work. In other words, some people may choose to move closer to work to avoid paying tolls, while others would prefer to move further out of town to take advantage of faster drive times. However, zoning rules that, for example, held up intensification around employment centres may prevent this from happening.

6. We don’t need congestion pricing in the first place.

Finally, some people argue that congestion pricing is unnecessary. There seem to be two main reasons why someone may hold this view:

  • Contrary to popular perceptions, Auckland’s not really congested enough to need congestion pricing
  • If we just got on and built a lot of roads, like, immediately, traffic would flow smoothly and there would never be any congestion ever again.

The first reason seems to have at least some evidence supporting it, but the second evinces an insane disregard for basic economics (induced demand), financial realities, and the laws of geometry.

Leave your views in the comments, or answer the following poll:

What are the preconditions for congestion pricing in Auckland?

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The alternative route

Congestion pricing has once again hit the political radar, with the news that the Auckland Transport Alignment Project has recommended it as an option to more efficiently manage the transport network. They find that variable road tolls – highest during peak periods on busy roads and low (or even zero) at off-peak times – are the single most effective intervention to improve traffic flow.

ATAP - Interim Report - Manage Demand

On the whole, it looks like support for the idea is on the rise, which is positive. That suggests that the work that Auckland Council’s consensus building group did a few years back has contributed towards a better public conversation on the issue. That’s good, as it’s a challenging idea to sell to people.

The NZ Herald’s editorial on the topic was tentatively supportive and showed a reasonable understanding of the core principles of congestion pricing:

Transport Minister Simon Bridges conceded this week, “we can’t keep building new lanes on highways. We will need a combination of demand-side interventions if we are going to deal with congestion over the next couple of decades”. He prefers the term “demand-side interventions” to taxes, tolls or charges but those are what it means.

Unlike the council, the Government does not advance these for revenue raising but for reducing traffic on the roads. It clearly thinks road rationing is more politically acceptable than revenue raising and the AA agrees. Feedback from members, it says, showed support for tolls as long as people could be convinced it was for congestion benefits, not simply revenue.

However, the Herald’s editorial also exhibits a common misunderstanding about congestion pricing, arguing that free routes must be available as an alternative to tolled routes:

The joint report for the council and the Government this week did not suggest how road travel might be charged. Mr Bridges said one option was to track all traffic with GPS technology which is being trialled in Singapore and Japan. But that implies no roads would be free at times the charge applied. Travel is a basic freedom. We could welcome the chance to pay to use a fast lane when we need one, so long as free lanes remain.

The Herald’s position is basically in line with NZTA’s existing tolling policy, which states that:

…a road tolling scheme may be established to provide funds for the purposes of one of more of the following activities, namely, the planning, design, supervision, construction, maintenance, or operation of a new road, if the Minister of Transport is satisfied that:

  • the relevant public road controlling authorities (including the Transport Agency) have carried out adequate consultation on the proposed tolling scheme;
  • the level of community support for the proposed tolling scheme is sufficient;
  • if an existing road is included in the scope of the tolling scheme, it is physically and operationally integral to the new road in respect of which the tolling scheme will be applied;
  • a feasible, untolled, alternative route, is available; and
  • the proposed tolling scheme is efficient and effective.

However, I think that both NZTA and the Herald are being too hasty in assuming that the untolled alternative route has to run parallel to existing roads. Alternatives can exist in time as well as in space.

Stu Donovan described the maths behind this last week. Transportblog reader Bryce Pearce also dug up a good practical example: apparently Singapore’s road pricing scheme allows people to travel for free most of the day. For example, if you are trying to drive on Lorong 6 Toa Payoh at 8:30am, you’ll have to pay $1. But if you leave an hour earlier or an hour later, you won’t pay anything:

ATAP took a similar approach when choosing how to model congestion charges. As the following diagram shows, the ATAP scheme would increase peak and inter-peak pricing, relative to current fuel taxes, but decrease charges in evening periods. Consequently, people would have options to save money for certain types of trips, for example, by shifting supermarket trips from the afternoon to the evening:

ATAP - Interim Report - Road Pricing Differences

Arguably, being able to travel for free on the same road, at a slightly different time, is even better than being able to travel for free on a different, more circuitous road at the same time.

There are obvious user benefits to the approach of varying tolls by time of day. It allows people to make better choices that respect their individual preferences for time, timeliness, and money.

But there are also important system-wide benefits from variable tolls between different time periods. Because congestion can be quite sensitive to changes in the number of cars on the road at a given time, encouraging even a relatively small number of people to shift the time at which they travel can lead to large benefits.

That’s nicely illustrated in the following graph of Auckland Harbour Bridge traffic volumes. The AHB is essentially free-flowing during the middle of the day, when there are around 1300 vehicles per lane per hour. But it is considerably slower during the evening and morning peaks, when the bridge carries more like 1500-1700 vehicles per lane per hour.

Lane Capacities

Because the peakiest bits of the peak are relatively short – perhaps 2.5 hours in total across an average weekday – you could improve the performance of the bridge by charging tolls during a few short windows. People could still travel for free (or at any rate a lower price) during the remaining 21.5 hours of the day.

From my perspective, that’s a pretty good alternative for drivers! But what do you think about the issue?

Congestion prices, carbon taxes, and the art of the possible

If you ask an economist about transport policy, it’s a certainty that they will mention congestion pricing at some point. It’s easy to see why. Currently, we manage our roads like a Soviet supermarket: access is rationed by queues rather than prices. As a result, we get inefficient outcomes.


The New Zealand transport system?

The theoretical and empirical case for congestion pricing is strong. In places where it has been implemented, such as London and Stockholm, it has increased vehicle speeds, improved accessibility, cut pollution, and improved safety. Not bad.

Because congestion pricing works, it tends to become quite popular once people can see the results. Although a majority of Londoners and Stockholmians opposed tolls at the outset, around 70% of residents in both cities now support them. But all of this raises a question: why haven’t more cities implemented congestion pricing?

I was thinking about this when reading a pair of articles that David Roberts (Vox) recently wrote about carbon taxes – and why they may not necessarily be the best policy for preventing climate change. Many of the points that he raises are also relevant to a discussion of congestion pricing.

In the first article, Roberts discusses the benefits of carbon taxes (efficiency) and the problems associated with applying them to complex markets. He argues that:

Believing a single tool will accomplish everything requires seeing the economy as a frictionless machine, a spreadsheet, not what it is: a path-dependent accretion of past decisions and sunk costs, to be tweaked and unwound.

As a result, it may make more sense to intervene more directly in specific markets – say, by regulating coal-fired power plants out of existence or subsidising alternatives. The equivalent in the transport space would be to manage congestion by cobbling together a raft of policies that look unrelated at first glance – e.g. transformative investments in rapid transit and cycling, bus lanes or high-occupancy-toll lanes on more roads, and higher parking prices.

In the second article, Roberts addresses a more challenging issue: politics and the art of the possible. He argues that carbon taxes are seldom effective in practice due to several factors that make implementing them and raising the tax to an effective level a risky proposition. These include concerns about distributional impacts, or the degree to which poor people will bear the impact, and low willingness to pay to avoid harms. Both of these factors seem potentially relevant to congestion pricing as well.

Roberts points out that many of the policy recommendations made for carbon taxes are economically sensible but respond poorly to political constraints. For example:

Many conventional economists, along with some of the few conservatives who take climate policy seriously, favor a “tax shift”: using the carbon tax revenue to reduce other taxes, preferably “distortionary” taxes like payroll or income.

The idea is that you double your impact: You get less of what you don’t want (carbon) and more of what you do want (work) — more efficient markets on both sides. Harvard economist Greg Mankiw is a big proponent of this perspective, as is Bob Inglis, one of the few conservatives actively working on climate change policy.

The main thing to note about tax-shift schemes is that they address few of the political barriers facing carbon pricing.

A carbon/income tax swap would be doubly regressive — raising a regressive tax to lower a progressive one. Reducing payroll taxes might have a net progressive effect, but it is very difficult to imagine the politics working.

In the past, I’ve taken a similar view on congestion charges. I’ve argued that we shouldn’t raise money from tolls. Rather, the revenues should be distributed back to households, and especially low-income households who might be most adversely affected.

But, Roberts suggests, offering to return the revenues will not necessarily make carbon taxes (or congestion pricing, I suspect) popular with the public. Instead, a more popular approach might be to tax something bad – e.g. carbon emissions or road congestion – and reinvest the revenues in something good, like renewable energy or better transport choice:

On the 2014 National Surveys on Energy and Environment, a carbon tax with no specified revenue use polled poorly. But things changed when different uses of the revenue were offered alongside the tax.

USA Today describes the results:

[A] different picture emerges when survey participants are asked about three possible uses of the tax revenue. If used to fund programs for renewable power like solar and wind, 60% back the tax overall, including 51% of Republicans, 54% of Independents and 70% of Democrats.

A smaller majority supports a tax if the revenue is returned to them via a rebate check. While 56% overall favor this idea, support ranges from 43% for Republicans to 52% for Independents and 65% for Democrats.

The third option — using the tax revenue to reduce the massive U.S. fiscal deficit — is not popular with any political group. It is opposed by the majority in each.

The same seems to hold true in the case of congestion pricing. In their excellent textbook on transport economics, Kenneth Small and Erik Verhoef cite surveys that find that people prefer toll revenues to be either reinvested in better road infrastructure or used to improve public transport.

This points to a paradox. The best way to get people to support such a scheme may in fact be to promise to put some tolls in place (albeit tolls that they can avoid by making different choices about how and when to travel) and then spend the revenues on giving them more transport choices.

Incidentally, I would stress the word choice in that sentence. There’s a reason why people want carbon tax revenue to be put towards renewable energy projects: it promises to give them options to avoid the tax altogether. In New Zealand, where 80% of electricity is generated from renewable sources, even a high carbon tax would have a small impact on households’ power bills. People in other countries would like to be in that same happy similar position.

The same is likely to be true for transport. If we implement congestion pricing, it might make sense to pair that with investments in public transport, walking, and cycling to allow more people to avoid the tolls. That will be more likely to lead to a win-win situation: People who value being able to drive on uncongested roads will get to pay a small price to do so, while everybody else will get to choose whether to pay the toll or travel differently.

What do you think about the politics of congestion pricing?

NZTA on motorways solving congestion

Last week the NZTA posted this video on their YouTube channel as part of a series talking about motorway works in Christchurch.

Not sure I could have said it better myself.