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Transport - general

Aug 1, 2017

Is public transport the only solution to congestion?

Public transport is a big part of the answer to congestion but it can't do it alone. But congestion isn't the only big issue; so is providing access to places as population grows

Population in the inner 100 sq km approx of six cities – Manhattan is the exception; it’s only 59 sq km, giving it a higher average density than central Paris

The Age editorialist reckons the $10 Billion Melbourne Metro rail tunnel now under construction is transformative infrastructure, but it’s not enough to deal with the city’s “congestion crisis” (Melbourne’s congestion crisis: The Metro rail tunnel is just not going to cut it):

A failure by successive Victorian and federal governments to adequately plan and to invest in public transport has created Melbourne’s most pressing and profound problem: congestion.

The writer thinks we should be dealing with congestion by building far more urban and regional public transport:

Multiple train line upgrades and extensions are needed… (The) ultimate solution to congestion is public transport.

The ultimate solution to traffic congestion is public transport, essentially rail? We certainly need to invest more in rail – a lot more – in order to handle projected population growth, but the solution requires more than that. Public transport is part of the solution but it can’t do it by itself:

  • Because building public transport infrastructure does not significantly reduce traffic congestion any more than building motorways does. The space vacated on roads by motorists who shift to the new train is soon taken up by other motorists i.e. induced demand.
  • Because the cost of retrofitting a public transport network that could attract all or even most travellers away from cars would be stratospheric. Paris has 303 stations within circa 5 km of the city centre; Melbourne has just 28 (see Can we build a metro just like the one Paris’s got?).
  • Because our cities are low density compared to the likes of successful transit-oriented cities such as Paris, Manhattan and London and we seem intent on keeping them that way. Paris has 2.25 million residents within the first 5 km; Melbourne has 430,000, most of whom resist higher densities (see How dense are our cities compared to Paris? and Is 16-storeys OK in the inner city?).
  • Because much larger and denser cities like Paris and Manhattan with outstanding rail networks are nevertheless still afflicted with serious traffic congestion. Drastically limiting car use is politically very hard in most places.
  • Because our multi-generational preference for private transport isn’t magically going to go away. Cars are currently much faster on average than public transport for all trips other than those to a few very dense places e.g. the CBD (see Is driving quicker than taking the train?). Autonomous cars promise to make driving even more convenient than at present (see What should we be doing now to prepare for driverless cars?). Electric vehicles powered by renewable energy sources will reduce significantly the environmental problems with cars (see Are electric cars a game-changer?).

The only way to tackle traffic congestion is to ration access to road space in some way. Some Chinese cities use odds and even number plate days without success; the obvious candidate is network congestion pricing. That can reduce the number of vehicles, increase average speed in the peak, and help make space for other road users like buses, trams and two-wheelers (see Is congestion charging just too unfair to bother with?).

The common argument is that congestion pricing can only be implemented if travellers have access to alternative public transport that’s as fast and convenient as driving. That condition would effectively rule road pricing out in Australian cities. However, it’s overly demanding; given driving is under-priced, there’s excessive car travel and hence no warrant for providing the same quantity of transit service. Moreover, motorists can shift the timing of trips to lower cost off-peak periods, or they can chain trips.

But reducing traffic congestion isn’t the only objective and arguably not even the main one; it’s a pity politicians and editorialists focus exclusively on it. The other key purpose is to increase access. New motorways eventually induce congestion at peak periods, but they increase the number of travellers who can get places, albeit slowly in the peak but faster in the off-peak. Public transport doesn’t “solve” traffic congestion either, but it excels at moving large numbers of people who want to go to the same place at the same time, albeit more slowly than driving in uncongested traffic.

If Melbourne really does grow at the projected rate (and that’s by no means certain), I think a number of key actions along the following broad lines are necessary:

  • Increase the supply and coordination of public transport; some new rail lines will be required but the weight of change must come from repurposing existing road space for high frequency buses and trams (see How can public transport work better in cities?).
  • Moderate demand by pricing access to the road network and encouraging vehicles to use motorways rather than high amenity streets. Given the scale of projected population growth, some increase in kilometres of motorway will likely be necessary.
  • Encourage a shift to more space-efficient private vehicles i.e. smaller, slower and kinder to others. The greatest promise is speed-limited electric scooters using dedicated road space. The priority shouldn’t be to eliminate all travel by private modes; it should be to eliminate large, fast, low-occupancy vehicles.
  • Require autonomous passenger vehicles to be shared (i.e. like a driverless taxi), powered by electricity, and charged by trip distance and time-of-day.
  • Reduce barriers to higher residential and employment densities in established suburbs, with greater intensity in locations close to high capacity public transport. Continue to permit well-planned incremental residential expansion at the fringe.

These actions should be supported by higher-level policy initiatives, especially shifting metro electricity generation to clean sources and removing taxation incentives that make housing as much about investment as shelter. The implementation would also vary spatially e.g. higher public transport mode share in denser areas; more private transport in less dense areas.

There are a few other claims in The Age’s editorial that I think warrant more explanation e.g. the idea that Melbourne Metro is “transformative”; and the charge that airport rail “has been forced off the agenda because of surging demand on the Sunbury and Melton lines”. The one I want to comment briefly on though is the claim that:

Evolving technologies will help ease Melbourne’s growing pains – ride sharing and driverless cars will probably reduce gridlock.

If they’re implemented on the current model of private car ownership – i.e. business as usual – I think it’s far more likely driverless cars will increase gridlock, not reduce it. That’s because they’ll significantly reduce the cost of travel. If you send your driverless vehicle up to the automated dispenser to pick up groceries while you sleep in, you probably don’t care too much if it sits in congested traffic for 30 minutes longer than it would off-peak.

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15 thoughts on “Is public transport the only solution to congestion?

  1. Jacob HSR

    You did not do an article on the oil slick on the cycleway?

    http://www.theage.com.au/victoria/cyclists-targeted-by-bike-path-oil-slick-vandal-20170731-gxm9nw.html

    She got damaged teeth as a result of falling over. How come the helmet did not protect her teeth?

  2. Peter Hill

    Alan, well argued by you. I am substantially in agreement with your analysis. The UITP released a strategy policy paper early in 2017 which assessed at a high “summary” the strategic environment of urban transport and the discontinuous rate of changes that autonomous vehicles (AVs) would induce in metropolitan transport choices and behaviours and also in land-use decisions. I made a public submission to “The Road Ahead”, Infrastructure Victoria’s policy development process, in which my assessment of the scenario of AVs was much in common with the findings of that UITP paper

  3. cud chewer

    Alan. Two things I’m compelled to point out (even though I agree with a lot of your suggestions including some form of congestion/usage charging).

    Firstly, you seem to take for granted that cars will generally outperform rail transport on speed. This simply does not have to be so. Rail transport can easily compete with car transport over medium to longer distances (15Km+). There are many journeys within Sydney and Melbourne that fall into this bracket.

    Secondly. Autonomous vehicles are a two edged sword. What you’ve failed to notice is that autonomous vehicles also provide a last mile solution for rail transport. Its the slow local bus service that faces extinction. Enter a door to door solution that involves both fast trains AND autonomous vehicles.

    In a city where autonomous vehicles provide a final address seevice, there is less need for walkable stations. At least, outside of CBDs. Longer station spacings (at least on new lines) means higher speed trains that are competitive with car travel over medium to longer distances.

    You see, the idea that we build more slow trains and let cars handle the longer distances is not only technologically dated, it fosters balkanised rather than unified cities.

    Cars are an inefficient use of space. This applies still even with the tweaks you suggest. And the biggest problem we have is the combination of car usage and car usage over medium to longer distances. Its the length of car jouneys that multiplies the space/cost of motorways. And its in the space of medium to longer distance journeys where trains can not only compete with car travel but make car travel a second class option.

    1. Alan Davies

      Cud Chewer,

      Yes, there has to be a much bigger role for public transport and yes, there are some trips that suit trains better than cars e.g. long trips to the CBD, where the high cost of parking and high traffic congestion, combined with being the focal point of the rail system, make driving much less competitive.

      But there’s no getting away from the fact that for the great majority of travel, car trips on average take much less time than public transport trips, including trains. Note VISTA shows public transport’s share of all weekday trips in Melbourne is 9%, whereas cars’ share is 72%. Road network pricing will help make public transport more competitive with cars.

      I agree autonomous vehicles could have a big role in addressing the last mile problem; they’re one reason why we shouldn’t have to spend squillions giving every Melburnian walk-up access to a rail station.

      1. Peter Hill

        Alan, I agree with your response here. I assume your reference to giga-expensive solutions for “walk-up” access to rail stations refers to expanding car-parking capacity next to rail stations. With the prospect of AVs, there is an even more pressing need to develop a dynamic time-of-day, by-distance and geographic location-responsive road pricing system upon all roads. Cordon-pricing, route-specific and “congestion” road pricing models per se will become even more irrelevant and passe.

  4. Roger Clifton

    We need to skip any concern over kilometres, and instead use minutes as our measure of convenience. Thus we want to be able to get to an adequate number of facilities in an adequate number of minutes. In fact, we only want congestion to reduce until our access is “adequate”, after which point we want congestion to increase to keep outsiders out, lest their intrusion threaten the adequacy of our own access.

    1. cud chewer

      Quite so. If private motorways were only allowed to toll based on average speed, their business cases would look rather different 🙂

  5. rohan storey

    Yep, we certainly need more than just rail, Im now a believer in buses, but especially of the rapid, dedicated lane sort, of which we have none. Brisbane has 27Km much of it on specially built roads and tunnels; we cant even provide that for the Doncaster buses !

  6. meltdblog

    On that Paris comparison of 303 Stations within 5km, if we count the number of Train and Tram stops within 5km of the GPO in Melbourne its 0ver 400 (many duplicate entries however) so we could say there is already a dense network of rail transport stops in Melbourne but most of them share the road space.

    1. Alan Davies

      Yes, tram stops share road space; so a long way short of the Paris Metro’s dedicated lines. Virtually all the Metro stations are underground too, so expensive to build in Melbourne when the cost of inner city stations approaches $1 Billion each. Paris also has some light rail surface stops.

      1. Damian

        I’m not sure that comparisons to Paris or cities of this size and density are very helpful. There are plenty of other cities of Melbourne’s size that do have metros (ie Montreal, Berlin). Sure, these cities are still more dense, but that only leads to my next point – that we’re not intent on keeping our cities low density at all. That 5km inner circle of the metro area referred to contains not only the CBD, Docklands and Southbank, but also Carlton, West Melbourne, North Melbourne (including the Arden urban renewal area), Fitzroy, Collingwood, Abbotsford, Richmond, South Yarra, Prahran, South Melbourne and the St Kilda Road precinct – all rapidly increasing in population and density. Then there’s the high density Fisherman’s Bend forecast to house 80,000 which will require densities greater than Paris. Just have a look at the cranes on the skylines of these areas, that 430,000 residents could be 800,000 in 20 years. And even if it takes longer, metros aren’t built quickly and rather than be reactionary, shouldn’t we be accepting and encouraging population growth in the central zone (rather than the fringe), planning decades ahead and putting adequate PT under all this growth before we reach the density of Berlin?
        Your comment that there is a multi-generational preference for private transport is also becoming less relevant, Millennials’ preferences are leading the charge towards PT.

        1. Alan Davies

          Damian, I think cities like Paris are the appropriate comparison because cars have low mode share in them. Canadian cities like Vancouver, although often cited as models, aren’t all that much better than Sydney when like is compared with like and where the measure is outcomes (e.g. mode shares) rather than policies and intentions e.g. see How does Sydney compare to Vancouver on travel?

        2. Woopwoop

          Look at a photo of Paris (or Vienna, or even London) and see that although dense, their inner cities have a human scale of buildings 5 or 6 storeys. In Melbourne, it’s either one or two storeys or 30. It’s not so nice.

  7. Amark

    3 weeks ago the age wrote that metro was being built to fast, and now its all happening to slow. The give voice to small NIMBY groups that needlessly slow down, increases the cost and lead to diminished outcomes for the wider community as a whole. And then wonder why circulation and readership is falling

    1. Gorkay King

      Yes, The Age is a bit of a joke these days.