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Let’s define “congestion” properly

An article in Toronto’s Globe and Mail newspaper just over a week ago, using the rather provocative title of “Sick of Congestion: build roads not transit” has unsurprisingly led to a lot of fisking of the information contained in the article – particularly around the different ways of defining congestion and how easily they can be misused. A good example of a response is this from Jarrett Walker.

Essentially, the argument put forward in the article is that when we look at cities around the USA (and internationally), at first glance the data appears to be showing that cities which have built a lot of freeways in the past few decades have lower levels of congestion than those which haven’t. Here are the key paragraphs:

This connection between road construction and congestion has been most comprehensively studied in the United States. There, 30 years ago, the Texas Transportation Institute at the Texas A&M University created an annual Travel Time Index (TTI) that estimates how much time traffic congestion adds to commuting by comparing actual travel times of commuters in different cities with the time it would take to travel the same distances in the absence of congestion.

Over the decades of its existence, the TTI has revealed some fascinating shifts. In the early days of the index, Phoenix, for example, had the 10th worse congestion among major urban areas in the U.S., despite being only 35th in population. It has more than doubled in size in the ensuing decades (it is now the 12th largest urban area in the U.S.), but its traffic congestion has fallen to 37th.

What explains this major improvement? A huge expansion of public transit? Hardly. Try a major road-building program. Something similar happened in Houston.

At the other end of the spectrum, Portland, Ore., has pursued road-skeptical policies similar to many major Canadian cities. The result is markedly worsened commuting times. According to the TTI, over the past 30 years Portland has gone from having the 47th worst congestion in the U.S. to the sixth worst.

Something in the next paragraph jumped out at me when first reading it – when mention was made of New Zealand cities as examples of those that had high congestion and hadn’t built many urban freeways.

Now data are starting to emerge that allow us to compare commute times among similar rich-world industrialized countries in Western Europe, the U.S., Canada, Australia and New Zealand. The results are not encouraging for the anti-car crowd. The worst urban congestion in this group of countries is in New Zealand, followed by Australia, countries that have invested relatively little in urban freeways.

If Auckland, with our gigantic spaghetti junction and motorways to just about every corner of the city, is an example of us not having invested much in ‘urban freeways’, I’d hate to see a place with lot of them – although Toronto’s Highway 405 (below) is pretty bad. I actually had a quick look at some figures from US cities with populations greater than 1 million people and from what I can tell based on some admittedly very rough calculations is that the size of motorway network would probably put us within top 10 US cities. Might have to look into that in more detail for a future post.

But the strange mention of New Zealand aside, the real issue with the article is its reliance upon congestion information from the Texas Transportation Institute that is decidedly dodgy in how it’s applied. Let’s pick up on Jarrett Walker’s criticism of the source data:

TTI believes that traffic congestion is a valid measure of people’s ability to access the resources of their city.  They do not measure actual travel times for all people, or the liberty and economic liberty that a good urban transporation system offers.  They apply these things as factors to a degree, but their bottom line is road congestion.

Specifically, their metric is the difference in travel times, by car, between travel time on congested roads and the same roads in a free-flow condition.   In other words, their baseline utopian condition is abundant free-flowing roads at all times of day.  (That condition is actually an economic impossibility in a city above a certain size with a healthy economy and no road pricing.)

Once you insist on measuring congestion, and against that fantasy baseline, you can get absolutely everything backwards…

… If you count everybody’s commuting time, Portland is ahead of most US metros.   … it is only congestion that is worse.  Yes, like all dense cities, Portland has exactly as much congestion as it makes room for, but it has low overall commute times, mostly because its carefully mixed density allows many people to commute very short distances.   Remember, if you are measuring car congestion, Portland’s transit riders and cyclists and the many people who can walk to work simply do not exist.  Crowley disses “congested” Vancouver for the same reason, even though Vancouver is the only Canadian metro where the long-term trend is toward shorter commute times, due to continued consolidation of housing and business around transit.

Jarrett sort of dances around the key point here while hinting at it in a number of ways. This key point is that for many people in the Portlands or Vancouvers of this world the level of basic congestion is irrelevant because they’re not affected by it. They’re walking, cycling, on a bus (as long as it’s in a bus lane or on a busway), a tram, a train or whatever. They’re not in the congestion.

This is the key point of the Congestion Free Network: it provides people with the ability to ‘opt out’ of congestion. This approach highlights that there are two elements to congestion:

  • How bad is the congestion? (Congestion intensity)
  • What proportion of people experience the congestion? (Congestion exposure)

It is the combination of these two elements which is what really matters – the actual effect of congestion can be increased or decreased not only through its intensity (which is all that the TTI measure, and arguably not that well either) but also through changing the proportion of people experiencing congestion. It seems that transport planners and particularly transport engineers focus so much on trying to reduce the intensity of congestion, even though this is nearly impossible due to induced demand, whereas the long-lasting way of reducing congestion is to provide ways to remove people from the congestion.

This means that a focus on cycleways, bus lanes, rapid transit and freight lanes (because it can be very important to shift goods around in a way that’s unaffected by congestion) are the true ways of reducing the actual effect of congestion. They’re also the only long-lasting ways of doing so. Todd Litman focuses on this distinction in his recent piece on Planetizen:

…the Texas Transportation Institute’s Travel Time Index, the INRIX Traffic Scorecard, and TomTom’s Traffic Index only measure congestion intensity, the degree that traffic declines during peak periods. Such indicators do not account for exposure, the amount that people must drive during peak periods and therefore their total congestion costs. Intensity indices are useful for short-term decisions, such as how best to cross town during rush hour, but are unsuited to strategic planning decisions that affect the quality of transport options or land use development patterns, and therefore the amount that people must drive. For planning purposes, the correct indicator is per capita congestion costs.

For example, a compact, transit-oriented city may have a 1.3 Travel Time Index (traffic speeds decline 30% during peak periods), 60% automobile commute mode share, and 6-mile average trip lengths, resulting in 34 average annual hours of delay per commuter; while a sprawled, automobile-dependent city has a 1.2 Travel Time Index, 90% automobile mode share, and 10-mile average trip lengths, resulting in a much higher 45 average annual hours of delay. Intensity indicators imply that the compact city has worse congestion due to greater peak period speed reductions, although its residents experience lower total congestion costs because they drive less during peak periods.

I talked about TomTom’s Traffic index here.

As part of the next phase of promoting the Congestion Free Network, we are going to focus strongly on expanding this new approach to defining congestion – so that it can actually be a useful measure of transport success, rather than something that suggests we do stupid things like building more (or bigger) urban motorways.

Highway 401 in Toronto

55 comments to Let’s define “congestion” properly

  • Barb Cuthbert

    Well done on this blog, Matt. It’s such commonsense, and exposes the political agenda behind so many proposed Auckland transport planning projects.

    Your photo of the Northern Busway says it all. The last photo could surely be of the future plans for the North Western motorway upgrading, showing that was is most needed is a dedicated busway and improved dedicated segregated cycleways for the NW Cycleway to provide improved transport choice.
    I’d love to see the approach you outline for congestion intensity and exposure used to transport modes for the western sector of the city to show why investment needs to be diverted into PT, walking and cycling. It would help our case to overturn AT’s poor design currently out for public consultation for the Lincoln Rd widening. What say Cycle Action and Transport Blog collaborate to push for it?

    • Frank E

      I believe the Lincoln Rd project is adding a new transit lane. I would’ve thought that’s a positive for you guys.

      • Gary Young

        It is a positive for everyone who travels on the road; not just for those of us who advocate for multiple, independent modes of transportation within cities.

  • Auckland can solve its problems by focusing on the actual cause of congestion.

    • Congestion usually stems from Toa when we have Auto Dependency rather than Transit Choice.

      Auto Dependency being: “Just a note: auto-dependency is not a choice – it is an enslavement from lack of choice. Cities should aim for auto-choice; where one is not overtly penalised by wanting and taking a choice between car, active or mass transit. Auckland does not currently provide that auto-choice as the City is an auto-dependent city. In simple terms how can you have choice if you are the dependency eliminates all and any other options.”

      You give a full suite of legitimate transit choices for a city to use in moving people and you will knock considerable amounts of congestion off. Back it up with some roading improvements (Waterview, Greville Road, Manukau-Takanini as some of the larger scale ones on the books) and you knock some more congestion off.

      Couple all of the above with proper land use planning (what happened to neighbour centres and dairies in the new subdivisions so you didn’t need to travel by car to the nearest Countdown for the milk and bread) and I say we are on to a winner in beating down congestion……

      • Autodependency is by circumstance, not urban design or enslavement (although when stuck on the Southern motorway it may seem that way). Auckland has a great motorway network by circumstance of its historically sprawled smaller communities turning into Cities overtime. In the past Auckland had a better Public Transport network because the actual city was relatively compact and automobiles expensive. Wellington has a very good PT network by circumstance of its Geography not urban design. London has a very good PT network by circumstance of its population density not urban design.

        • Toa Auckland has a motorway motorway network not by circumstance but because we decided to build it. We latched on to building motorways faster that most other cities and never stopped while many other cities started investing in other modes again in the 70’s as they saw the impact the motorway networks were starting to cause.
          Wellington has an ok PT network (I wouldn’t call it very good). Yes Geography played a part but is not the only factor. As for London it’s underground is the result of needing to move a lot of people, something that there simply wasn’t enough space for on the surface (and surface rail lines were banned from inner London).

          • Absolutely, our auto dependency is 100% due to planning and design and 0% due to circumstance.

            Before the motorways were designed, funded and built all of Auckland proper was on a tram network, while all but one of the regional villages were on the rail lines or ferry.

            Then we decided that we would be a car based city, we started designing and building motorways and arterial roads, we changed planning laws to make the most walking and transit friendly neighbourhoods illegal and ensure the only type of dwelling you could build was on a dispersed, low density cul de sac form at the end of a hierarchy of roads.

            The fact that we removed 15,000 intensive dwellings from the central city fringe (an area where transit was highly successful, and walking to work and services was the norm) and replaced them with a motorway junction that severed the remaining neighbourhoods to facilitate new car based fringe suburbs kinda underlines that point.

            Or the fact we built a road only harbour bridge without so much as a footpath, then proceeded to subdivide the north shore into dispersed suburban lots where driving was the only practical means of travel.

            There was no ‘circumstance’ about it, our auto dependence was entirely planned and designed. The simple fact is, at the time, they thought that autodependence was a good thing and that having everyone drive for all their transport would be ideal

          • Which of course it can be, to a certain scale, and with an acceptance of a certain level of death, injury, and a great deal of expense. I wonder what the maximum size of a town is in order for it to function efficiently at near total auto-dependency (ignoring all the other dis benefits)? Small provincial town? Population of < 200k? Too low? The highly dispersed nature of Christchurch maybe can so long as long commutes for such a low population are considered acceptable?

            After all there has been no point in Auckland’s history that the road lobby hasn’t campaigned for more roads, will there ever be? No, it will always be chasing its tail, because like some medieval doctor prescribing blood letting, its cure causes more injury to the patient. And, of course, yet more work for the ‘doctor’.

          • Frank E

            Patrick, there are successful cities in the US which rely completely on Cars. Houston and Dallas both have populations greater than 6 million and they both are doing well, have travel time to work around par compared to other cities in the US.

            TBH I’ve yet to see any statistics that prove that auto dependant cities have significantly longer commutes as you claim vs cities with decent transit.

            http://www.bloomberg.com/visual-data/best-and-worst/longest-commutes-us-cities

            If you look at the median travel time table you see sprawling cities doing pretty well (Houston, Dallas, Orlando etc.) whereas ‘transit friendly’ cities like New York, Chicago do have longer commutes.

          • ‘Successful’ yet full of constant complaint about travel times and congestion, Houston and Dallas both trying, rather hopelessly, to retrofit light rail into their dispersed geographies, and Atlanta the very worst of all worlds: totally auto-dependent, very long commute times, huge road and parking investment, highly congested. These cities are also over represented mortgage foreclosue stats with whole distant suburbs being ‘underwater’. Especially Phoenix and the Central Valley in California, which are also highly sprawled and auto-dependent. Auto-dependency is highly inefficient at scale.

            You are still only using the TTI measure of ‘success’, not an wider understanding: simply a comparison of driving times at 3am and 5pm. Over simplistic.

          • I just refreshed myself on the 1950s AT Master Plan and 1960s De Leuw reports which proposed greater motorway networks and PT (De Leuw) for the rapidly sprawling outer Auckland surburbs.

            Tramlines were replaced with buses probably because it was considered progressive and more efficient at the time. The Harbour bridge may have been built without train capacity as post WWII finance would have been very limited and expensive to build new train infrastructure. The fact that clipons were retrofitted means there was some future proofing to take advantage of easing future financial conditions.

            A main reason why the proposed extensive Motorways and PT networks were not built would have been due to financial circumstances of post WII decades.

          • Frank E

            @Patrick Can you show me the proof that Atlanta has ‘very long commute times’. I’ve had a look around and can’t find anything that shows that.

          • “The average working adult in Atlanta’s suburbs now drives 44 miles a day! That’s 72 minutes a day behind the wheel, just getting to work and back. 94% of Atlantans commute by car. They spend more on gas than anyone else in the country.” page 185 Happy City Charles Montgomery 2013.

            The point in the main body article is that if the TTI counted everyone’s commute, including all those who walk, bike, or take transit, then the cities with mode choice, Vancouver, Portland NYC, would score way better than the highly dispersed auto-dependent ones. The results of this over simplistic measure are are a complete result of excluding everyone not in a car. It is, frankly, a biased and one sided measure. And therefore all but useless.

          • Frank E

            Firstly I agree the TTI measure isn’t the best. The average travel time to work including all modes is the better for measuring how well the transportation network is.

            As for Atlanta, 36 minutes each way is quite long though large numbers of people do seem to be willing to pay that price as Atlanta’s suburbs do continue to grow. TBH I’m not particularly sure how accurate that data, as the map link I posted below has most of Atlanta’s suburbs having lower commute times than that. The map is census bureau data so I presume its accurate.

          • Interested to know if all these figures include walking and cycling, or is it just motorised trips?

          • Frank E

            If you follow the links than it comes to this page which does show walking and cycling as an option so I presume that data is in there.

            http://www.census.gov/newsroom/releases/archives/american_community_survey_acs/cb13-41.html

    • Frank E

      Did you even look at the link? I was talking about the mean travel times which has nothing to do with the TTI definition of congestion which I agree is an inefficient metric.

      Your first point that they complain about travel times and congestion, well is there any city in the world where people don’t complain about travel time, I know NYers do even though they have a comprehensive Rail network.

      As for adding rail to these cities, Houston’s small network does pretty well (which is more of an urban network) though I agree that adding Light Rail to suburbs is probably not the best idea which is what Dallas did. However this is pretty much the same as cities like Portland and vancouver does.

      I’m no expert on the foreclosure crisis though I don’t think it was caused because cities were over auto-oriented. I know Texan cities were not hit that bad by the crisis are they’re some of the biggest auto oriented cities.

      I do agree with you that congestion isn’t a good measure of how good a cities transportation network. The mean travel time to work is probably the best metric that is available.

      • The problem with that measure is it is actually measuring an outcome of at least three factors, the effiency of the transport network, the distribution of employment, and the physical size of the city. A physically bigger city with most jobs downtown means longer average travel times whichever way you look at it. There are other factors there too, like the economy. Journey to work times in Detroit are great, only because the city is dying and hardly anyone is going to work any more!

        You’ll note that Portland has the fastest commute times, presumably because it is relatively small and compact as well as having an efficient and fast transport system. The difference between Portland and New York probably has to do with the fact that the Portland commuter belt is about 25km in radius while the New York commuter belt is over 100km in radius.

        • Frank E

          Portland does have fast commute times though it is worth noting that cities that are significantly larger than it, like Houston have commute times that are very close to it.

          It is nice that you admit concentrating jobs at a single place does lead to greater commute times and the associated costs with it both economically and socially and that leads us to the question whether its worth pursuing this model. Are there enough benefits of concentrating jobs to offset the costs.

          To finish off this is an interesting interactive map of commute times by ZIP code in the US. One thing that is quite interesting is that the difference of commute times between inner city areas and suburbs usually isn’t that big.

          http://io9.com/5988852/an-interactive-map-of-average-us-commute-times–how-does-yours-rank

          • My comparison was between small and large city with centralised employment (i.e. Portland vs. New York). The same can be said for a comparison between small and large cities with decentralised employment too. The large city with decentralised employment will have longer average travel times whichever way you look at it.

            Concentrating jobs in a single place could lead to greater commute times, but doesn’t necessarily. Concentration allows for efficient rapid transit for a start, that’s close to impossible with major decentralisation. Having a poorly planned decentralisation scheme can be far worse, where you have people driving right across the region to access employment (I know a guy who bought a house in Papakura because he worked in a Manukau regional office… then got transferred to the Henderson regional office. His journey to work time is around 75 minutes on average in the car, if he worked in town it would be 53 on the train). It’s a bit more complex than simply centralised = bad and decentralised = good.

          • Not so fast there Frank, decentralsing employment makes for long commute times too; just across town rather to into town, what fixes commute times [by whatever mode] is mixing up employment learning and living everywhere. Exclusionary zoning is the problem not its distribution. On balance a strong centre is better than flat distribution, NYC v. Phoenix, as at least then a majority of trips to the centre are, by definition, closer to most points than otherwise, and it’s cost effective to saturate that place with transport alternatives.

            I have a friend who lives in Waimauku, just did up his house, then suddenly got a new job at Fonterra; in Takanini: 130km daily commute. No wish to leave house, likes new job, would be much better for him if his job was in the CBD. Bought a new smaller car just to try to minimise the gas bill. Decentralised employment isn’t working in that case.

          • Frank E

            If you build enough infrustructure than a centralised city could have pretty good commute times but I think practice shows that centralised cities like NY, Chicago do have high commute times. It just becomes too expensive to build the infrustructure.

            Secondly I do think transit and decentralisation can work together if you think of them a number of job clusters rather than a completely even distribution of jobs over a city. Most European cities don’t have a single cbd and they certainly make transit work though population density does also play into that.

            Lastly more decentralisation probably does lead to more super commutes but the average commute does seem to even out to be lower than comparable centralised cities. The Dallas region has a weak cbd but maintains low commute times and looking at the map they are reasonably uniform across the region.

          • Frank E

            @Patrick, I 100% agree that we should mix residential and commercial as much as possible.

          • I’m not necessarily arguing with your point Frank, but I don’t think you can say the evidence shows that cities like NY and Chicago have high commute times because the are centralised. Cities like NY and Chicago have high commute times because the are enormous metropolises with about twenty million and ten million inhabitants respectively.

            Dallas-Fort Worth is about two thirds the size greater Chicago and less than a third the size of New York.

            If you took the central third of New York’s population and compared that to the Dallas of the same size and shape you’d probably find New York performs at least as well.

            I would also question whether the likes of New York could be considered centralised anyway.

          • Well there it depends whether you mean multi-centred or just dispersed. The former clearly can work well for transit, the later, not so. Density matters and scale is a factor in both.

          • Luke C

            Companies often shift premises, stranding workers. Eg Officemax moved from Constellation to Highbrook, many who would have had 15-20 minute commute will have well over an hour and can forget about using PT. Same with new Sleepyhead factory planned in Manukau, replacing Avondale facilty. Not much fun if you live in Te Atatu or Henderson.
            Decentralisation of jobs also can mean many things. If it is multiple regional CBD’s then thats fine, but if its vast mixed areas of offces and warehousing with no centre like East Tamaki and North Harbour this is hopeless for everyone involved.

          • Sleepyhead used to be in Grey Lynn and employed lots of locals; now a countdown and terrace houses.

          • Frank E

            @Nick R Maybe a better comparison would be New York City which has roughly the same population as the DFW area.

            @Patrick Businesses naturally gravitate to each other so of course there will be ‘multiple
            centres’. I can’t think of any city that has jobs completely evenly distributed across a region.

            @Luke C I am curious at how warehousing can be done ‘transit friendly’. It naturally leads to lower densities so it certainly is more difficult. Maybe an idea for a post one day.

  • Bryce P

    We need to have those mwy travel time info signs include the PT travel times at the same point during rush hour.

    • JimboJones

      We need a good PT network first! I can’t imagine many of those PT travel times being quicker unless you happen to live and work near a train station.
      Our work recently moved to Penrose and because of the terrible traffic in the area most employees looked at their PT options. In almost all cases, taking PT would more than double the amount of time as driving.

      • bbc

        Catching a bus from the North Shore into the city is considerably faster than by car, as is the ferry from Devonport. There are many points in which PT is faster, furthermore, the motorway signs then also ignore the time taken at each end to find a park, pay for the park, park the car and walk to the destination. Certainly that’s generally not the case in Auckland, but when a good quality congestion free PT option is offered, people flock to it. Ironically the savings from the reduced road capacity needed (e.g. from the Shore) simply gets funnelled back into more roads somewhere else rather than into PT.

        • Yes this is what makes those signs so disingenuous: What happens to your car at the top of Nelson street once you’ve got there in x minutes? Does it just evaporate? Does the NZTA really only work for the owners of private inner city parking spaces?

          Bullshit math I say NZTA.

          • Frank E

            You could say exactly the same thing about timetables, couldn’t you. You don’t just vanish when you get off the bus/train..

          • I’m not suggesting people vanish, but the train or bus does, you don’t have to find a park for your vehicle when using transit, don’t you see? The motorway timeboards suggest that there is always a zero time cost to parking. This is clearly not true, especially in the city centre.

          • Especially in the city centre, you usually need to drive to a parking building, park and then walk to your destination. With PT you go straight to the walk to your destination bit.

          • Frank E

            Well most people do park in the same building or very close to their place of work so that last walk probably isn’t that far.

        • JimboJones

          When you say ‘there are many points in which PT is faster’, I think you pretty much named the only ones (the trains, the ferries and the northern). Considering the majority of Aucklanders only have access to the bus network, and that network is a shambles with hundreds of confusing routes all going the longest way possible with as many stops as possible and bus lanes that seem to disappear at the most congested points, I think putting those times on the travel time signs would only prevent people taking up PT!

  • JimboJones

    If a magic fairy were to offer the city of London to replace all of its underground train lines for big overground motorways, I wonder how many Londoners would vote for that? And if they did, I wonder how many Londoners journey times would improve? Not many – if any?

  • In short, we will get more of whatever we build for:

    1. More motorways = more driving = more congestion + a less resilient and duller city

    2. Invest in the alternatives = more choice = less driving = less exposure to car congestion = more vibrant and viable city.

    In terms of quality of the city it also represents a choice between a monoculture like a cultivated pine forest versus the biodiversity of a rain forest.

  • Barb Cuthbert

    Spot on, Patrick. Happy New Year to you.

  • Greg N

    I wonder if may need to consider a change to the message around the CFN slightly, when talking about a “Congestion Free” Network
    – which to many people (Government and AT transport planners included) means lots of empty road space for cars and trucks
    – who will never have to slow down for anything else i.e. something like those empty busway lanes except with the pesky bus removed.

    The better message might be one of a “Congestion Impact-Free” Network whereby the majority of people never have their travel plans impacted by congestion.
    (unless they choose to e.g. by taking your car into the CBD at peak instead of the PT alternatives.)

    Which is more akin to what the post is saying – don’t measure just the congestion and assume everyone as if everyone only ever drives.
    Measure the throughput of all modes combined then and only then when all the modes are congested call it Congested.

    Its a sad fact that right now if you were to show many people the first photo with the “empty” bus lanes in it, and you asked them if there congestion in this photo and what should we do about it?”
    They say “Yes theres a lot of congestion, And to fix why not allow those cars to use those “wasted” bus lanes?”

    Which defeats the whole purpose of the bus lanes if you do that. But does show the simplistic messages people get given all the time, that more roads/lanes is the only solution to congestion.

    That photo and its captions also reinforce the same message – “Congested” means full of cars and “Congestion free” means empty/mostly empty roads..

    But many people don’t see/understand that the people on the bus have no experience of congestion as they cruise by the occupants in their cars – which is true.

    The second photo is also interesting – as a visual explanation of what a CiFN could mean using that Mega-Motorway shot.

    If you look down the middle of the Motorway there are 2 empty lanes – one going each way.

    If you were to explain to people, that if you were to put high capacity PT (e.g. a rail line) down just 1 of those empty lanes, you could completely empty all those 10* lanes of traffic next to it of cars – if everyone driving a car used the train instead. Thus leaving more than a few lanes left over for all the trucks to use instead.

    (* technically its 9 lanes each way in the photo, but who is counting – it looks like 10 lanes, and in any case there are 10 lanes there, it just one of the 10 lanes, is free of traffic).

    Or as another explanation, use it to show that if you don’t have the train line – you’d need those 10 lanes of motorway (or 3 lanes of bus-ways or whatever it is) to achieve the same effect
    – i.e. exactly like that photo shows, no high-capacity PT and 10 lanes of traffic (each way) needed as a result.

    • We’ve had an internal debate about the name congestion free in the past along similar lines to what you have pointed out however have chosen to stick with it seems to resonate with most people and is also why we want to expand the definition of congestion and congestion free this year.

      • PS1

        And we could also add to the list for a Congestion Free network – localism. People who dont’ get in their car much because they have good local schools, local jobs and local food stores. Investment in local communities and town design improves congestion.

      • Greg N

        Leave the name, just change the messaging around it slightly.

  • Jacques

    Good post! what silliness lies hidden in statistics… It’s hard to imagine that the people who used these congestion numbers in the first place made an honest mistake, more likely that they were actively trying to deceive their audience.

  • grantb

    Although commuters can potentially opt out and take a bus or other modes of transport, the TTI congestion will still impact on transport industry and other vehicles like courier drivers and tradespeople. Must be frustrating for say a plumber to get to the first job in the morning and getting snarled up in commuter congestion with all those people one per car.

    I imagine there must be some interesting feedback cycles – the more congestion, the more people seek alternatives including time-shift with early/late starts, then peak congestion reduces, encouraging more people to take cars at peak times… and so on. I thought though that Auckland congestion measure had decreased in the last 10 years. Found one reference here: (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10873207) but I still looking. I presume this is due lots of improvements to motorways (e.g. Victorian Park tunnel, onramp lights) as well as increased PT usage?

    Guess the TTI is just one measure that just needs to be balanced against others.

    What is AT’s primary goal? Reduce total commute time (including via mode share)?, reduce peak delays etc.

    • Steve D

      A lot of contractors work e.g. 7.30-4 (which also matches up slightly better with daylight hours), so generally they’ll have just arrived at the first job before the morning rush, and then hopefully not have to drive again until after the peak.

    • Sailor Boy

      I would have thought britomart and the busway were more helpful

  • The Globe & Mail article comes as no surprise, with the author’s close ties to the Canadian Tories.

    http://thetyee.ca/Opinion/2011/03/21/CrimeFloggers/

  • Time is not the only cost of course, there’s also space, and in a city that space is more valuable, that’s pretty much what a city is- a place where space is more valuable. Here is a graphic from Happy City that shows that competition for space:

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