What can we do about traffic congestion?

The Federal Government’s State of Australian Cities 2010 Report was released yesterday.  It says the avoidable cost of traffic congestion in Australia’s capital cities was $9.4 billion in 2005 and is expected to rise to $20 billion by 2020.

What can we do in a city like Melbourne about congestion? There are four basic ways to address the issue:

  • Increase road space
  • Shift travellers to a less-congested mode
  • Suppress demand for road space
  • Manage the level of demand

The first approach involves building more road capacity e.g. new or widened freeways.  However people seem to have an almost inexhaustible demand for travel, so as soon as a route gets faster due to added capacity, it pretty quickly fills up again until once more it becomes congested.

The second approach usually involves attempting to shift drivers out of their cars and onto public transport.  Traffic congestion is positive for public transport because it undermines the cars speed advantage.  The problem however is that any road space liberated by travellers shifting to public transport is soon filled up by other drivers as per point one above.  Moreover the customary assumption that the alternative mode isn’t itself congested doesn’t always apply e.g. Melbourne’s currently overloaded train system.

The third approach is to suppress demand.  This is what happens at present with traffic congestion – the road effectively becomes clogged and can’t carry any more cars.  The key downside of congestion, however, is that it slows everyone down equally.  High value trips – like say a job interview, a funeral, an important business meeting,  a load of freight – are slowed as much as comparatively low value trips like driving teenagers to school or doing the daily shopping during peak hour.

The fourth way involves a number of measures but the key one is road pricing – requiring drivers to pay a charge (toll) for road space, with prices higher during peak periods.  Drivers making high value trips at peak hour will be more inclined to pay for the privilege while those making low value trips will have an incentive to seek out alternatives, such as possibly not making the trip at all, scheduling it for an off peak period when the toll is lower, or shopping once a week rather than every second day.  Some trips could even be taken by walking or public transport rather than by car.

Road pricing is the most sensible approach. The main disadvantages are the charge that it is inequitable and the reality that it would be difficult to implement politically – drivers get angry at having to pay for something that they’ve always regarded as free.  I plan to deal with these issues in a future post.


14 Comments on “What can we do about traffic congestion?”

  1. Alan,

    (1) Increasing road space increases traffic … no long term solution there, I agree

    (2) A shift to less-congested modes is of value …
    [a] move non-essential government department to outer-urban centres … in Brisbane it is absolutely obscene the number of non-essential government CBD workers needing to commute to the city daily
    [b] time-shift non-time critical travel … change working hours, enforcing only core time to spread the load, and provide off-peak travel price advanatages

    (3) Suppressing demand is probably best left to the “Delay Vs Importance” balance … congestion controlling outcomes

    (4) Favours the advantaged over the disadvantaged … for example, a disadvantaged government worker needing to move to outer areas to find accommodation, is then forced to drive to a central office block to offset the lack of public transport in the “new estate” outer area.

    If Melbourne finds an answer then package it and sell it widely.

    • Alan Davies says:

      Hi Greg, thanks for some interesting ideas.

      The issue of moving government workers out of the CBD is, perhaps surprisingly, more difficult than it looks. That’s why it doesn’t happen much in spite of the obvious political advantages. I might address this in a future post, although in a nutshell there are big losses in economies of scale (in information).

      Time shifting does happen to some extent and I agree there’s more potential there. The Vic Government recently introduced free public transport for travellers who finish their journey before 7am. Modest but apparently has had some effect, although its hard to tell if the rise in early patronage is due to this incentive or the overcrowding at peak hour.

      I’m actually preparing a separate post that touches on the issues you raise about the equity of road pricing. I’ll post that soon.

  2. Benno Spearritt says:

    They’re all bad ideas except “shift travellers to a less congested mode”.

    You correctly point out Alan that the public transport system in Melbourne is already congested. However with some modest and inexpensive changes, it can rapidly become a less congested mode. Also a more efficient mode.

    By “modest” and “inexpensive” I mean compared to options 1, 3 and 4 which would all have significant undesirable economic and social externalities, not to mention establishment costs. By inexpensive I also mean that it would be a high fixed cost but low maintanence cost with huge positive externalities.

    It is good for humans to travel to other places often and efficienty for business and leisure. Options 3 and 4 can’t support this.

    Rail is still the most energy efficient form of transport ever invented for distances between 3 – 2000 kilometres; and the fastest form of transport up to 500 kilometres (for comparison including mucking around getting too and from airports and town centres; whereas rail takes you right in).

    If vacuum tunnels on the sea floor ever become feasible, then rail will be the most efficient form of transportation for distances between 3 – 20,000 kilometres; New York to London in half an hour for neglible energy spend compared to an aeroplane. You could even be clean shaven by the time you arrive.

    Using the epping/hurstbridge corridor as an example, If:

    #Collingwood and West Richmond stations were abolished.

    #Dennis and Westgarth stations were amalgamted to a position between Mason and Jamieson streets.

    #Fairfield station was upgraded to a major stop like Jolimont and Ivanhoe.

    #Tram lines were laid from Fairfield Station up Station Street until Darebin road, whereupon they take a right hand turn and then a left to continue along the Darebin creek corridor all the way to La Trobe university. Tram stops to occur no frequently than every 500 metres, making it much more efficient than the 86. (Substantial land aquisition required, but hey, they’re only the working class!)

    #Rail line completed to Doncaster East with stops at Balwyn North (currently 40 minutes brisk walk to either Hurstbridge or Lilydale lines), Bulleen, Templestowe Lower and Doncaster.

    #Doncaster East line to link in at Victoria Park station as there’s heaps of extra room for two more platforms.

    #Having removed unnessarily close stations in inner city suburbs and upgrading track along the entire network. Trains during peak hours on the Epping, Hurstbridge and Doncaster East lines to run every 9 minutes. So that a train goes through Victoria Park every 3 minutes.

    #Next step of course is to increase rail capacity at Flinders Street and the city loop. But that’s all managable, if of high fixed cost.

    • Alan Davies says:

      Benno, I agree the rail system can and must be improved in Melbourne. It will have a larger role in the future but is most unlikely to have the majority role (I’m planning a post on why, shortly, but bear in mind that it only carries 10% of all trips ATM). I like the sound of your plans for the Hurstbridge line!

      Better public transport still leaves the issue that cars will fill up the space vacated by drivers shifting to public transport. Road pricing has an important role in managing demand – I don’t buy the argument that all trips are necessary or sufficiently valuable to justify their social costs.

      I think the vertical equity issues with road pricing are not at all straightforward and will post later this week to that effect.

      • Benno Spearritt says:

        I agree that rail systems just about everywhere will for quite a while fall short of majority transit status. As I see it, this is because there are roads everywhere, deliciously wide roads, which conveniently lead to places, lot’s of places. In fact, almost anywhere you want to go you can get there by driving a car on a road. There are freeways and back routes and rat runs and loop roads. Very delicious, I’m salivating just thinking about it!

        Whereas, rail, although as I said above is superior, it takes 10 or fifteen minutes (or more) to walk to the station. Then you have to wait for a train (10 minutes) and then you stop every 800 metres. It’s also very indirect for all but a few journeys (albiet including suburbs to cbd). There is no rail network. Cities have been designed around the world with car networks in mind (or for the older cities like Rome, greatly modified/retro fitted with car networks in mind).

        The London tube gives a modest example of the alternative. You can go from one side of London to another in an hour involving several (3, 4, 5) changes of trains. All changes are lightning quick, but necessary for the ultimate efficiency of not just getting from A to B but also to C, D, E, F etc… or almost anywhere between.

        “Better public transport still leaves the issue that cars will fill up the space vacated by drivers shifting to public transport.” – I don’t see how this matters at all; more people going more places more often. Better yet, it’s a great political argument in favour of increased rail funding.

        For some misguided reason, the RACV are firmly against public transport receiving more funding (in proportion to it’s share of trips) compared to roads. If you like to drive, surely it’s nicer when there are fewer people on the road because some more of them are on PT.

        Not wanting to contradict what I said above: Have there been any studies on at what point roads spaces stop being filled up to capacity? Surely there is an overall saturation point for transportation within a finite area with a finite population? There are only so many trips that people are willing and able to complete, regardless of how little congestion there is.

        “I don’t buy the argument that all trips are necessary or sufficiently valuable to justify their social costs.” – To this Alan, I can only say STANLINIST! : ) – that topic would make for a great post I’m sure.

  3. Benno Spearritt says:

    As for the Eddington suggestion of a train line from the loop to Melbourne Uni, if a few unnecesssary tram stops were removed on Swanston Street between La Trobe Street and Grattan, then what should be a 5 minute tram trip would actually be a five minute tram trip and not take 20 minutes, 10 minutes of which to pass the city baths.

    • Alan Davies says:

      My understanding is that DoT reckon this line, from Footscray via Parkville to The Domain, is needed to overcome capacity limits on the system.

      • Benno Spearritt says:

        Excuse me for being old fashioned but I don’t buy that line from Eddington/DoT.

        Why doesn’t the government just overcome capacity limits on the system by increasing capacity limits on the system? Namely the city loop and flinders street station.

        On a related capacity issue – I find the capacity constraints for pedestrians at Melbourne Central Station (once they’ve gotten off, or before they get on a train) to be dangerous and scary.

        A couple of peak hour train cancellations the the platform is packed, consequently with many people too close to the edge where they are more likely to meet with an accident. The platforms there need to have another 3 metres added as a matter of urgency. Never mind that tunneling is expensive.

        Also what would be greatly appreciated is screens with automatic sliding doors to prevent injury and death and to encourage more social behaivour – letting others off the carriage first. These are used to great effect in Singapore. Every station in Melbourne that is subject to crowding is in need of these.

  4. Alan Davies says:

    Looking back over this article, there’s another way of responding to congestion that I gave short shrift. That approach involves progressively expanding the boundary of the city with more houses and more dwellings. Because jobs and other attractors like hospitals and universities have also ‘decentralised’ massively over the last 70 years or so, most people most of the time travel within the suburbs relatively close (in car terms) to home. In this case congestion is defeated by low density.

  5. […] Probably the best that can be done – and it would be a big improvement – would be to implement road pricing in Melbourne. Workers who travel long distances to work would pay the social cost of their travel; employers who […]

  6. […] thinking about. Charging motorists for road space, particularly in peak periods, warrants even more thinking. -37.781700 […]

  7. […] cars will still cause problems like traffic congestion. One way of addressing that problem is charging motorists for the right to drive during congested periods. This would facilitate high value trips during the […]

  8. […] public transport improvements. Road pricing is something I’ve advocated on a number of occasions (here and here), but what particularly caught my eye in Mr Dowling’s article was his opening […]

  9. […] congestion pricing, particularly the equity effects, which I’ve discussed before (e.g. here and here), but there are ways of addressing […]


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