Two more days this week have shown just how vulnerable our transport network is because of the lack of viable alternatives.
There was chaos on Auckland’s roads once again on Wednesday. Unlike the major incident a month or so ago on the Newmarket Viaduct, this time there appears to have been number of factors that combined together to cause massive problems for motorists. While there was talk about the bomb scare, personally I think the impact on traffic from would have been fairly minimal in the grand scheme of things seeing as Queen St has so few vehicles on it these days. Other factors like the horrendous weather and people trying to get away for an extra-long weekend are likely to have had a much bigger impact. However while the events that triggered the chaos might be different than what caused issues just over a month ago, the cause is the same, there are simply too many cars on the roads. Roads can only handle so much traffic before even the slightest incident can cause chaos and it feels like our roads are that level now.
So if our road network is already straining under the weight of cars it really makes you question how people can predict that traffic volumes will continue to grow substantially. Yet that is exactly what our transport models predict is going to happen. Even with the best case scenario of City Rail Link as well as improved bus infrastructure, our models predict that by 2041 the number of peopled moved by private vehicles in and around the city centre will increase by over 20%. The improved bus infrastructure will take further space away for private vehicles, which means those extra vehicles will be even more concentrated on some roads.
Of course as we know there are some serious issues with the modelling however even if just half that increase in traffic were to eventuate, what would happen to our roads. How will that change people’s perceptions of driving vs catching a bus or train? Despite what our models say, how realistic is it for us to substantially increase the number of cars that are able to around? Will we start seeing these massive congestion incidents turn from a being one or two times a month to a daily occurrence?
Unfortunately yesterday there was another incident, this time on the southern motorway where tragically someone lost their life. This naturally led to a lot of congestion as the motorway needed to be closed so that an investigation could take place.
As mentioned at the start, our transport system is extremely vulnerable to these issues. Building more and more motorways and wider local roads aren’t going to magically solve issues. Nor are tweaking traffic lights like suggested by John Roughan this morning in the herald (although at least he admitted that another harbour crossing isn’t needed). These measures will just allow people to reach the end of the congestion traffic queue faster. Properly investing in alternatives is the only real option we have that can give people some certainty to their travel times. Lets also not forget that these both occurred during school holidays, a time when there is usually a lot less traffic on the roads.
There has been quite a lot of discussion recently about the “cost” of congestion, as well as pretty dire future projections in relation to levels of congestion 20-30 years in the future. But, compared to other elements of transport costs, how does congestion actually stack up? Todd Littman takes a look at this in a really comprehensive study that has been summarised on the Pricetags blog:
Comparing Congestion With Other Costs
The UMR report claims that traffic congestion wastes “massive” amounts of time and money, estimated at 5.5 billion hours and 2.9 billion gallons of fuel, worth an estimated $121 billion.
Described this way the costs seem very large, but measured per capita they appear more modest: 17 hours, 9 gallons and $388 per year, or less than three minutes, 0.03 gallons and $1.06 per day. These represent less than 2% of total travel time and fuel costs, which is small compared with other factors that affect per capita travel time and fuel consumption costs.
This indicates that congestion is overall a modest cost, larger than some but smaller than others:
Because congestion is just one of many costs, it is inappropriate to evaluate congestion reduction strategies in isolation: a congestion reduction strategy may provide far less total benefit if it increases other costs, and is worth far more if it reduces other costs or provides other benefits.
For example, roadway expansions may seem cost effective considering just congestion impacts, but not if wider roads induce additional vehicle travel which increases other external costs. Conversely, improving alternative modes may not be cost effective based only on their congestion reductions, but are cost effective overall when co-benefits (parking cost savings, traffic safety, or improved mobility for non-drivers, etc.) are also considered.
Somehow we need to get past using congestion as the primary success/failure measurement for transport. After all, not only is it seemingly relatively minor in the scheme of things, but there’s a fairly good argument out there that congestion doesn’t hold back economic productivity:Ultimately it’s hard to work out what the real cost of congestion is, but I’m pretty sure it’s WAY less than we assume.
Brian Rudman has hit the nail on the head with his piece this morning and raised many of the same points we frequently do:
But let’s not allow the authorities to persuade us that last Thursday’s logjam was a one-off event, and to pin the blame on the drivers involved in the motorway pile-up.
When I read of motorists woes in Friday’s paper, my first thought was, well, welcome to the club. On Monday, I had waited in Albert St for my 5.05pm bus, and when it failed to show, caught an Inner Link at 5.20pm, which then took 45 minutes to crawl up the short trip to Three Lamps, Ponsonby.
The journey wasn’t helped, by a New Zealand Bus car, parked illegally as usual, by a clipboard wielding “inspector”, slap bang in the middle of the bus lane outside the Victoria Park Markets. By week’s end, someone must have talked to her. I last spotted it parked illegally on the footpath in front of the bus shelters instead.
My planning guru, one of the “seen it all before” school, assures me everything will settle down in a week or so, as students start either sharing cars, find the parking problems are too great, or sleep in and start missing early lectures, that sort of thing. Here’s hoping.
Of course in a city with better separated public transport pathways, gridlock on the roads would be manna from heaven. What better promotion for the merits of public transport than a stalled and steamy motorist, trapped in their car, while a bus or train speeds past in their dedicated bus way or rail track.
In a year or three, when the new electric train service finally arrives, a part of this dream will become reality, and start luring commuters out of their cars. But for buses – the main form of public transport here – a network of separated bus lanes remains a pipe dream. Especially when even the bus operators treat what fragments of bus lanes that do exist – such as the one outside the Victoria Park Market – as a joke.
While Thursdays traffic problems were certainly larger than normal, they were by no means the only day that there are issues. The NZTA reports of accidents happening across the motorway network almost daily on their twitter stream, like this one from today.
Not all incidents create major problems but invariably there can be significant local congestion, this is especially the case when roads are near capacity. When that happens it doesn’t take much for traffic jams to form and even someone braking or changing lanes can send a shockwave of congestion back down the the roading network, as this video made by Japanese researchers shows.
The reality is we simply can’t build our way out of congestion, and no city has been able to do so. As Patrick described the other day, one of the big benefits of investing in better public transport is that it can take the edge off the roading network. Its not about each mode competing against each other but them working together to get the best outcome for everyone. But for PT to do its share and help take that edge off, it needs to be a better option in all situations, not just in the peak but also off peak, weekends and for events. One of the biggest things needed is much more extensive priority measures to at least keep the higher capacity PT network flowing.
He comes to the conclusion:
After several years of steady growth, public transport usage is starting to decline. At the last Auckland Transport board meeting, the bureaucrats presented plans for a marketing programme, complete with billboards telling us to “get training” and “get moving”.
Now I’m no marketing whizz kid, but I am a frequent passenger, and my instant response to being told to “get moving” is, chance would be a fine thing. I would, if I could find a regular bus service to move me.
Before fancy double decker buses, we need buses that turn up on time – or at all. We need electronic indicator boards that don’t lie and frustrate. And we need dedicated bus lanes in and out of the city so that be it Mad March or the depth of winter, buses can actually flow.
I agree, the best way to market PT services is not fancy marketing campaigns, or double decker buses but to get services working as people expect them to and having them run on dedicated bus lanes, especially on the parts through the centre of the city. I’m not aware of a single metre of new bus lane that has been added in the last few years, although some of the existing lanes have definitely been downgraded. So come on AT, lets get serious about getting these bus priority measures sorted.
We spend a lot of money each year trying to “fix” congestion in Auckland and across New Zealand. In fact, it seems that the bulk of transport spending in this country has “fixing congestion” as its ultimate aim – which is a little odd as research from the USA shows that the most congested cities are the cities with the highest levels of economic productivity. But even if we decide that traffic congestion is a bad thing, the next question that comes into my mind is “how bad?”
What level of impact does congestion have on the functioning of Auckland? To what extent would Auckland’s economic performance be improved by the reduction or elimination of congestion? What does “uncongested” actually mean? If traffic congestion ‘costs’ us a particular amount each year, what is the comparison with – empty roads?
A research paper prepared for NZTA helpfully attempts to answer a lot of these questions and to structure a much better informed debate over the true cost of congestion – particularly in Auckland. A lot of this debate, as the paper notes, comes down to definitions – what is congestion?
The purpose of this research was to develop improved approaches to assessing the costs of urban traffic congestion and to make corresponding estimates of the costs of congestion in Auckland (New Zealand).
Various definitions of congestion were reviewed and it was found that the concept of congestion is surprisingly ill-defined. A definition commonly used by economists treats all interactions between vehicles as congestion, while a common engineering definition is based on levels of service and recognises congestion only when the road is operating near or in excess of capacity. A definition of congestion based on the road capacity (ie the maximum sustainable flow) was adopted. The costs of congestion on this basis are derived from the difference between the observed travel times and estimated travel times when the road is operating at capacity.
It is interesting to look at this ‘definitions’ issue in more detail to gain an understanding of what congestion actually is. I find the debate between the economist’s definition and the engineer’s definition – as noted above – pretty fascinating because the economist’s definition potentially leads to the construction of more roadspace (as the threshold for congestion is lower) whereas most transport economists would probably feel more nervous about building additional road capacity than traffic engineers would.
I actually agree with the engineering definition because building a transport system to ensure that no vehicles impact on others is just plain stupid and impossible, while the real impact of congestion beyond a certain level is a reduction in the efficiency of the system – that is once you pass an optimal level the number of people/vehicles that can pass across a certain point begins to reduce. As the research paper notes, at zero speed there is zero flow. This is shown in the graph below:It’s only the bottom half of the graph above (speeds lower than about 42 kph) which actually indicates congestion in my opinion – where the efficiency of the network is reduced because it has become completely overloaded. The research paper takes the same viewpoint.
Applied to Auckland, we actually find that the current speeds on parts of the network analysed are pretty damn close to the most efficient (i.e. maximum flow) speeds – as shown below:Using this information, the pieces of the puzzle about how much congestion really costs Auckland can start to be put together:I’m not entirely sure how relevant the “schedule delay cost” is to working out the economic impact of congestion on Auckland, because it seems like these trips were still taken in an efficient way just not necessarily at the most desirable time. But in any case, using a reasonable definition of congestion highlights that while $250 million a year is quite a bit of money, it’s perhaps a bit less than is often spouted (that $1 billion a year figure which apparently comes from a 1992 survey that unsurprisingly looked at comparison to free-flow (i.e. empty motorways) traffic.
What would be really helpful is to get an idea of where this $250 million of congestion impact happens and who it happens to. If it’s largely impacting on people in far flung suburbs who would just sleep in if their commute was a bit shorter, then I don’t think Auckland’s likely to benefit too much from eliminating/reducing it. However, if the impact is on commercial vehicles (trades vans, couriers, time-sensitive deliveries etc.) then there might be a benefit from reducing congestion.
So overall, I think what I take away from this research is a couple of things: firstly, that congestion is probably not as bad as we had thought if we use a more sensible definition. And secondly, that perhaps we still don’t really know much about the linkage between congestion and Auckland’s actual economic performance. While nobody likes being stuck in traffic jams, for some reason we seem happy to throw billions of dollars a year at trying to fix this problem without even working out whether it’s a problem in the first place, how bad a problem it is or even whether what we’re doing is making things better or worse. To me that seems pretty reckless and dumb.
There’s been a lot of discussion after Auckland’s roading network completely collapsed on Thursday due to a crash on the Newmarket viaduct, which caused huge delays.
More than two hours later, traffic on almost all of the city’s arterial routes was gridlocked, with buses backed up in city streets and motorists reporting speeds of less than 10km/h.
Journeys that normally took 15 minutes were taking more than an hour.
Automobile Association traffic spokesman Phil Allen said he had never seen traffic so bad in central Auckland.
The association launched traffic-mapping technology on its site 18 months ago. Routes marked in black show where traffic is moving at under 25 per cent of the speed limit. “I have never seen so much black in the CBD. I’ve never seen anything like this.”
Having the Newmarket viaduct blocked off just before rush hour during the busiest week of the year for traffic (March madness) is pretty much a “perfect storm” in terms of things that can go wrong. Interestingly the train system ran just fine throughout the event because of its fundamental separation from the roading network – whereas most bus route in the area got completely nailed by the delays as they spread from the motorway network onto the local roads.
Len Brown’s comments in the Herald highlighted that while events such as what happened on Thursday are incredibly difficult to plan around, the ‘fragility’ of Auckland’s transport network to events like this is a really big issue and something improved public transport would help reduce:
Mayor Len Brown said the gridlock showed “why we need to invest in an integrated transport system including trains, ferries and buses”.
“Only through initiatives such as integrated ticketing, our new electric train fleet and the City Rail Link, can we unclog our roads and unlock the potential of Auckland.”
Cameron Brewer’s comments are, unsurprisingly, less sensible:
Auckland Councillor Cameron Brewer said he had to miss the Orakei Local Board meeting because of the traffic. He left the Town Hall at 5pm, spent 40 minutes on Hobson St, opted to take the Northwestern Motorway, got off at St Lukes and made his way across town to his home in Ellerslie, arriving an hour and 45 minutes later.
“When the airport western ring road to Waterview is complete that will take some pressure off SH1, but what that one accident shows is just how reliant almost all of us are on cars, and that’s not going to change much in the foreseeable future.
“It should be a real wake-up call to the mayor as to where the real problems and frustrations lie for most Aucklanders – that is in traffic jams.”
Mr Brewer said he’d like more improvements to the motorway network and more bus lanes, ferry terminals and cycle and walkways, rather than the CBD rail tunnel.
While the Waterview Connection is a project that would help a lot in situations like this – by providing that much needed “alternative route” – unless Mr Brewer is advocating for a return of the Eastern Motorway project I can’t quite see how further motorway improvements would change what happened on Thursday. And he should have just taken the train to the Local Board meeting as it was held not too far from the Meadowbank train station.
And it seems like the chaos has continued today – not helped by Auckland Transport’s stupidity in not running anything better than hourly trains across much of the rail network even though there are a huge number of events on in Auckland.
As a country we spend a lot of money on transport, at three levels: central government, local government and personally. In the 2012 budget, around $3.8 billion of expenditure on transport by central government was proposed. Further to that, transport is generally the biggest item of expenditure for local government – the Auckland Council spends over half its money (more than half your rates bill) on transport each year. Plus we obviously spend a lot of money ourselves: paying for petrol, buying cars, fixing cars, registering and warranting cars, paying for parking, paying for insurance, bus fares and so forth.
Obviously at an individual level we pay because we need to get around. Plus we need stuff to get around as well, so that we can get that stuff ourselves. I’m not going to go into the amount we pay for transport individually much in this post – except perhaps to point out that transport costs that are worn by individuals clearly varies and the impact of different transport decisions we make, especially different funding priorities, has an impact on the amount we may need to pay at an individual level. For example, if the public transport system is good enough for one member of a family to rely on for every day commuting, then maybe that family only needs to own one car instead of two (or three) – and therefore they avoid the need for a massive expense in owning, fueling and maintaining that car.
So why do we spend a heap of money (by my reckoning, only social development, health and education would be funded more by central government) on transport? At a high level, it’s so that we can achieve benefits to society that cannot be achieve if there was no public agency managing the revenue collection, planning and implementation of transport improvements (though crazy libertarians will always disagree with this). Each government of the day tends to outline what its broad goals are at a general level, with policies designed to help achieve those goals. The current government wants to focus mostly on boosting the country’s economic performance and productivity. The Auckland Council wants to make Auckland the world’s most liveable city.
Where it becomes really interesting is the next step down – how does transport policy and spending help to actually achieve these broad levels goals? This obviously requires specifying a number of transport goals that contribute to achieving the over-arching vision – whether it be the government’s vision or the Council’s vision. The government thinks that spending big money on reducing traffic congestion on the roading network – particularly parts of the network that are busy freight routes (or, by the look of it, busy during holiday weekends) will make a huge difference to economic performance. The Council’s vision also focuses on reducing congestion, but suggests that this is likely to be best achieved through the creation of an outstanding public transport system and better integration of the transport system.
Occasionally, the two visions conflict – something which doesn’t please the government at all:
Given the cost and the forecast increase in congestion, despite this substantial investment there are fundamental questions over value for money and whether the right mix and timing of projects has been chosen to address forecast travel patterns. A priority for the Auckland Council, potential funders and infrastructure users is to reconsider the proposed projects and undertake the strategic review to determine whether individually, and as a package, they are the right projects to address the long-term transport challenges facing Auckland.
This view is consistent with the official Government response to the Auckland Council, released in July, which noted “… the Government also remains to be convinced that the programme as a whole represents the right mix of projects and will provide value for money. To improve the prospects for alignment on transport policy, the Government encourages the Council to review the proposed projects to ensure the transport strategy is optimised to address forecast congestion under the likely land use pattern”.
I actually strongly agree the Council needs to undertake such a piece of work, but the outcomes of the review might end up being the complete opposite of what the government thinks – the removal of a large number of pointless and eye-wateringly expensive roading projects.
But all of these plans are based on an assumption that reducing traffic congestion will actually lead to better economic growth and/or better liveability. Those are actually assumptions worth testing – as did an article in Atlantic Cities a few months back, which looked at the link between congestion and economic performance. The results will surprise some:The article explains the relationship, which actually shows that per capita GDP is higher where there’s more congestion:
…regional GDP and traffic congestion are tied to a common moderating variable – the presence of a vibrant, economically-productive city. And as city economies grow, so too does the demand for travel. People travel for work and meetings, for shopping and recreation. They produce and demand goods and services, which further increases travel demand. And when the streets become congested and driving inconvenient, people move to more accessible areas, rebuild at higher densities, travel shorter distances, and shift travel modes.
Stated another way, people adapt to congested environments. Because cities provide greater access to job opportunities than do rural areas, as well as wages that are more than 30 percent higher than their non-metropolitan counterparts they have a powerful economic incentive to do so.
Economic development is also intricately related to the density of employment – agglomeration benefits as they are commonly known. Putting more people in close proximity will inevitably lead to more congestion, but the negatives of that congestion (if there actually are any) are seemingly more than outweighed by the benefits of density.
Well what about Council’s assertion that reducing congestion will lead to improved liveability? Well just yesterday Mercer released their 2012 list of the world’s most liveable cities - with Auckland doing really well at number three (for the fourth year running). Let’s take a look at the top 10:
- Berne & Sydney
The bulk of these cites are dense European cities, which generally have quite a lot of congestion due to their limited road network in the inner areas (although obviously they tend to have pretty good transport choices). Other cities that do well include Vancouver, which decided to not build any motorways in its inner areas, and Copenhagen which is famous for being the world’s best city for cycling.
Perhaps what I’m really getting at with this post is highlighting that perhaps we’re focusing on the wrong thing in trying to achieve the ultimate goals of investing in transport? In both achieving stronger economic growth and better liveability, what if relieving congestion actually doesn’t help much? What if it actually undermines our efforts? What if it uses up a whole heap of money that could be better used on transport interventions which actually would assist in achieving the high level visions of both Central Government and Auckland Council (like encouraging greater employment densities or encouraging greater transport choices or reducing the amount of money we need to personally spend on transport so we can spend it more usefully elsewhere)?
For some reason an assumption has been made that reducing congestion will magically result in these strategic outcomes and therefore we need to focus on transport spending almost exclusively on the reduction of congestion. Well I’m calling bullshit on that assumption. And as there’s billions of dollars at stake here, we need to do better, quickly.
Another fascinating book that I am reading at the moment is “Road to Ruin: an introduction to sprawl and how to cure it” by Dom Nozzi. Like my previous post on How Cities Work, the key point made in Road to Ruin (at least so far) is how important the transport decisions we make are in determining the nature of our urban environments. This is picked up on really early:
Whatever a community makes its main form of transportation profoundly shapes the way it will use its land, not the other way around. Weak land use plans and feeble regulations did not create urban sprawl, for example: pouring money into roads and cars did. And whatever transportation our community chooses – for most of us, cars – also shapes our quality of life. As we have learned over the years, single-mindedly choosing car transportation has dispersed and isolated us and degraded our communities’ quality of life, environment and financial health.
I think most of the bloggers on this site are actually interested in transport because of its impact on the nature and function of Auckland, rather than for is own sake – although there certainly is an “awesomeness” factor to projects like the City Rail Link which certainly excites me.
The impact of transport decisions on our land-use in almost inadvertent ways is well encapsulated later in the opening chapter:
Faced with existing or projected congestion, we widen a road from four lanes to six or enlarge an intersection to the point where it is nearly suicidal for pedestrians to use the crosswalk. Because the bigger road is less safe and less pleasant for people to bike or or walk on or even catch a bus on, more of them choose to drive their own cars and to make more car trips, which puts more cars on the road – the additional car travel generated by the widened road or enlarged intersection becomes an after-the-fact justification for the widening. Because the widened road now carries more high-speed traffic, housing values decline along the road, and owner-occupied single-family homes get converted to rental units, offices, and business like convenience stores and pawn shops.
In a nutshell this is also the concept of induced demand that we have discussed on many occasions. As driving is made more attractive, and other modes less attractive, unsurprisingly people will switch to driving and the road will clog up again. Just as an aside, an interesting question that has been rolling around in my head for a while is whether induced demand still applies when you no longer have increasing travel demand – perhaps that’s something we can explore and debate in the comments.
Another really interesting observation that Road to Ruin makes is in relation to congestion and air pollution (including CO2 emissions). There’s a fairly widespread assumption around that reducing congestion will reduce pollution and emissions because of less ‘stop-start’ traffic, but that’s perhaps only true when you look at the issue from a very narrow perspective:
On the one hand, congestion creates more air pollution at the microlevel… On the other hand, people who live in higher-density, more ‘traffic congested’ areas (where transportation choice is high) produce much less air pollution and consume much less gasoline than those who live in remote locations with more “free flowing” traffic conditions who can use only cars for travel.
Congestion has gotten a bad rap, in my opinion. Indeed, traffic congested conditions can move us toward more liveable communities. For example, such conditions reduce regional air pollution from cars. They discourage ‘low value’ car trips and car dependency so increase bus trips, walking and bicycling, encourage public transit and transportation choice in general, large because strong political pressure is directed at elected officials to improve alternatives to car travel. Congestion reduces the average driving speed, as well as citywide fuel consumption. As downtowns because not just places to ‘drive through’, these areas become more pleasant for pedestrians, businesses and homes. Finally congested conditions promote compact development and infill and discourage sprawl; given the 1.1 hour commute-time average, people want to live closer to their destinations in the face of congestion.
Our current government’s narrow minded focus on eliminating congestion as pretty much its only transport goal obviously runs against pretty much everything in the previous two paragraphs and is a big reason why government finds itself making so many completely and utterly stupid decisions when it comes to transport policy. Somehow we need to “undemonise” congestion so that it can be seen as a useful travel demand management tool that encourages efficient transport and urban form outcomes. I guess to put it simply, if a motorway is pretty empty and has freeflow traffic at peak times, then that’s probably a sign we didn’t really need it to be that wide (or there in the first place).
I think I’ll probably end up writing a few more posts on this book as I make my way through it. There are certainly a lot of useful facts and figures further in that I’ve skimmed over. I guess the fact that it was published in 2003, nearly a decade ago, means that it is still in the “we need to change the way things are going” rather than the current paradigm of transport and land-use which I think is much more “we need to allow the changes that people are wanting”. It’s definitely a good and informative read though.
An article in yesterday’s Herald highlighted a few of the worst spots across Auckland when it comes to congestion:
The section of the Southern Motorway which merges with the Ellerslie Panmure Highway is the most likely to suffer traffic delays, according to a traffic monitoring company.
The SUNA Traffic Channel analysis of major metropolitan roads also revealed the top six worst areas in New Zealand were in Auckland.
The company took speed and vehicle data from thousands of probe vehicles earlier this year to make the assessment.
The Southern Motorway’s South Eastern Highway exit was the country’s second most problematic.
The Great North Rd and Rosebank Rd exits on the Northwestern Motorway and the Tristram Ave and Constellation Drive exits on the Northern Motorway also suffered delays.
I’m not surprised that this section of the Southern Motorway comes up as the worst spot on the network. It’s not just the severity of congestion at this point which is a problem, but also the extent of the congestion timewise. It’s often stuffed on a Saturday, quite early in the afternoon, well after/before peak hours and so on.
The congestion, particularly northbound, seems to be caused by too many vehicles entering the Southern Motorway within a pretty short distance. Northbound merging onramps from the Southeast Highway (around 18,000 vehicles per day) and the Ellerslie-Panmure Highway (around 12,000 vehicles per day) really just dump too many vehicles onto the motorway within a short period of time for it to cope.
Interestingly though, the number of vehicles per day on this section of motorway has been steadily decreasing since 2007:
Data from here.
Despite the falling traffic volumes, NZTA still has a project in place to widen the section of northbound motorway between Ellerslie-Panmure and Greenlane, as noted in the article:
The NZ Transport Authority’s regional traffic manager, Kathryn Musgrave, said the agency had introduced a number of significant changes to ease congestion.
These included plans for an additional fourth northbound lane on the Southern Motorway from the Ellerslie Panmure onramp through to Greenlane.
I can probably live with such a project, as it seems there’s still a big problem even if volumes aren’t growing anymore. The real question is whether small, seemingly desperately required, state highway projects such as this one can still get funded when most of the budget is going on the Roads of National Significance along stretches of road with less than 10% of this section of motorway.
There’s an interesting report, written by the Manager of Transport Strategy Kevin Wright, in the agenda for Wednesday’s transport committee meeting that looks at congestion in Auckland. In terms of the headline issue, congestion, the report notes that congestion levels are around the same as they were in 2004 (despite how much we have spent on widening and extending motorways). Compared to most Australian cities, congestion in Auckland is relatively low – but at the same time travel time reliability is much poorer than our counterparts across the ditch.
Congestion measures are often flawed though, as for example a road completely free of congestion at all hours of the day probably means we were stupid and spent way too much money in it. It’s helpful to see the report note the limitations of measuring congestion and suggest some ways that assessing the impact of congestion could be done better:
Traffic congestion cannot be represented by a single indicator. To get a broader understanding of congestion, consideration needs to be given to:
- the needs of the user at different times of the day, and by location;
- the performance of the system in terms of the throughput of people and goods;
- the role of the transport system in the economic and social well-being of Auckland (including productivity, access and the costs of travel);
- the extent, intensity, variability (including reliability and predictability) and duration of congestion; and
- the extent to which transport options which can avoid congestion (rail, bus priority lanes, ferries etc.) are utilised.
To accurately assess the ‘impact’ of congestion, a combination of the level of congestion with the proportion of trips experiencing congestion needs to be assessed. For example, while Fanshawe Street in Auckland’s city centre is congested at peak times, approximately 80% of people travelling along Fanshawe Street in the peak are utilising the bus lanes and therefore able to avoid experiencing the delay and trip unreliability caused by congestion. This situation significantly lessens the impact of congestion along Fanshawe Street, even though congestion still exists for general traffic.
This idea of measuring the impact of congestion, rather than just reduced travel speeds for general vehicles compared to what they might be able to do in a theoretical “free-flow” scenario, which once again is nigh on impossible and financially reckless anyway, seems like a really positive step forward. If hardly anyone has to put up with congestion, then the extent to which it is something we need to worry about reduces.
Even more positively than this, the report also picks up on something we’ve talked about a lot on this blog in recent months – the slowing of traffic growth over the past few years. A table in the report highlights that since 2005 the growth of vehicle kilometres travelled on the state highway network in Auckland has slowed considerably (from 3.4% compound growth between 1998 and 2005 to around 1% compound growth since 2005): The report also includes the graph on state highway traffic volumes across New Zealand that we’ve often discussed – which shows a decline in volumes between 2005 and 2011: There’s some interesting discussion around whether this flat-lining is caused by long-term issues or short-term issues, which obviously has huge implications looking into the future. No call is made on whether traffic growth will simply return once the economy picks up again (although from memory the economy was doing OK between 2005 and 2007 yet the growth in traffic had already slowed by then) but possible long term shifts such as cultural change, whether we’ve reached a saturation level of travel, ageing populations and a renaissance of inner city living are all discussed, along with rising fuel prices, as reasons for the flat-lining. There’s also a graph that highlights New Zealand is not alone in experiencing this phenomenon:
The scary implications of all this is highlighted right at the end of the report.
Modelling of future land use and transport scenarios for Auckland forecasts approximately 46% increase in motor vehicle use between 2011 and 2041 assuming full implementation of the transport programme and a high population growth forecast. Modelling takes into account expected population growth, increases in economic activity, increases in fuel prices and traditional travel preferences.
Distinguishing between the ‘short-term’ and ‘long-term’ causes of these recent trends is necessary to determine whether, once the global economy recovers, historical traffic growth trends will return or not. If longer term causes of the recent trends are significant, then future forecasts of vehicle demand may need to be revisited.
If we’re basing the spending of billions upon billions of dollars of money on transport projects over the next 30 years on projections which ignore possible longer term shifts in preferences away from travelling by car, then that seems like a pretty obvious thing to be looking into.
While NZTA and the Ministry of Transport remain in blissful ignorance of all this, it’s somewhat heartening to see that the Council recognises this as a key issue that could fundamentally change how we make future predictions and therefore how we prioritise future transport projects.
Logic says that higher densities will lead to more congestion. Concentrating many more trips within a smaller area may be more efficient (less need for so many roads and a greater role for public transport, walking and cycling) and as more people catch the train or ride the bus along exclusive bus lanes, congestion becomes irrelevant to an increasing number of traveller, but typically we’ve often thought that even taking all that into account it’s inevitable that you’ll see more congestion as you increase densities.
A recent study by the Arizona Department of Transport, highlighted by Todd Littman in this excellent Planetizen piece, questions that assumption. The first part of the results – that people in higher density neighbourhoods drive less than those in lower density neighbourhoods, is not that surprising:
[The study] found that residents of higher-density neighborhoods in Phoenix, Arizona drive substantially less than otherwise similar residents located in lower-density, automobile-dependent suburban neighborhoods. For example, the average work trip was a little longer than seven miles for higher-density neighborhoods compared with almost 11 miles in more suburban neighborhoods, and the average shopping trip was less than three miles compared with over four miles in suburban areas. These differences result in urban dwellers driving about a third fewer daily miles than their suburban counterparts.
But where things get interesting is the follow on finding from the study:
However, the study made an important additional discovery. It found that roadways in more compact, mixed, multi-modal communities tend to be less congested. This results from the lower vehicle trip generation, particularly for local errands, more walking and public transit travel, and because the more connected street networks offer more route options so traffic is less concentrated on a few urban arterials. This contradicts our earlier assumptions.
Littman’s article argues that the key difference higher densities make relates to the availabilities of transport alternatives, which means that as congestion gets higher people are able to make different transport choices. In lower density areas such alternatives simply aren’t available so everyone has not choice but to continue suffering in congestion. Put higher densities together with other key elements of smart growth – like mixing land-use types, improving transport options and having a highly connected street network, and you have the ingredients for lower congestion than you’d think:
Not only does smart growth significantly reduce automobile trips, by offering better accessibility options it allows people to respond to congestion by shifting mode and route. For example, when congestion is a problem you walk or bike to local stores rather than driving to a more distant shopping center, some commuters shift to alternative modes, and motorists can shift to less congested routes for some trips. These solutions are not possible on newer suburban communities where destinations are dispersed; walking, cycling and public transport inferior; and hierarchical road networks channel all traffic onto major arterials.
This has important implications for transport and land use planning. It indicates that smart growth development policies have smaller costs and greater benefits than usually recognized, including local and regional traffic congestion reductions, but it also indicates that these benefits are contingent; they require an integrated set of policies including increased density, mix, connectivity and transport options. As a result, the best response to smart growth criticism is more smart growth, for example, more density and mix, additional pedestrian and public transit improvements, more connected transport networks, more parking management, and additional incentives to shift travel mode.
Critics often assume that smart growth consists only of increased development density. If that were true then some of their criticisms could have merit, but it is inaccurate, as discussed in a previous column, An Inaccurate Attack On Smart Growth. Smart growth involves a combination of increased development density and mix, more connected paths and roads, and improved transport options. Together, these land use reforms can provide a host of direct and indirect benefits.
All the more reason to contain Auckland’s urban sprawl I guess.