Cars & traffic

Oct 18, 2012

Is “Effective Speed” a useful concept?

"Effective Speed" relates travel time to hours worked and, at first glance, seems like an interesting perspective. Closer inspection suggests it's neither especially insightful nor particularly useful.

Alan Davies — Editor of The Urbanist

Alan Davies

Editor of The Urbanist

Empty America - what San Francisco would look like without people

I might be late to the party on this one, but until I read this article on The Conversation this week, I hadn’t heard about the concept of “Effective Speed” before.

As explained by Dr Paul Tranter, a geographer at UNSW, Effective Speed takes into account all the time costs of a mode of transport, not just the in-vehicle time.

He says the time spent earning the money to pay for a car is usually much greater than the time actually spent driving. He cites this anecdote:

Imagine living in a village, where your job each day is to collect a bucket of water from the river. This takes an hour each day. To “save time” you build a machine to fetch the water. However, to make the machine work, you need to spend two hours each day winding up a spring.

In modern cities, he says, the equivalent of “winding up the spring” is the time spent at work earning the money to pay for transport. Driving to work might be considerably faster than using public transport or cycling,

However, motorists might be spending one or two hours per day (or more) earning the money to cover the cost of their cars, while cyclists spend only a few minutes per day earning the money to pay for their bicycles.

The term Effective Speed sounds very much like “Effective Density”, another relatively new and modish term. Effective Density combines job density and commute time in a single statistic.

I’m wary about the justification for combining a mere two ideas – both of them quite simple and straightforward – into a new and unfamiliar concept. Effective Density seems like an idea searching for a rationale (perhaps it’s about marketing more than anything else).

But at least Effective Density is conceptually logical. I’m not so sure the same can be said of Effective Speed. At first glance it’s appealing but on reflection it appears to be more illusion than logic.

It’s sensible to think about the full cost of transport (e.g. owning and operating a car) in terms of hours worked or money earned. But it’s not clear that comparing hours worked against hours spent driving adds anything or is even a useful way of thinking about transport.

To begin with, travel time leaves out a long list of other reasons people have for owning and operating a car. It’s not just speed – cars are attractive because they’re available on demand and go direct to the destination.

They also enable multiple passengers to be carried, as well as various objects like shopping or spare underwear. They offer privacy and personal security, protection from the weather and a high degree of comfort. Many drivers are also prepared to spend more (i.e. work longer hours) on a car  in order to communicate status.

Any metric that doesn’t factor in these attributes has limited explanatory power. My reservations go further though – what I don’t get is the premise that there’s a direct and special relationship between hours worked and hours spent driving.

Consider this example: I might work for six weeks to pay for a one week luxury holiday in the best hotel in Paris. The cost matters because I have to be able to afford it and I want value for money.

But how is evaluating the choice in terms of the length of the two time periods particularly important or illuminating? Is the trip not worth it because it’s much shorter than the time I have to work to pay for it? What matters is that I think the overall bundle of benefits exceeds the costs.

I suspect Effective Speed only seems appealing because both sides of the equation involve time. But if it’s a useful idea it ought to work for all the activities we labour to support.

What does it mean if I work one week a month to pay the mortgage? Or to pay school fees?  Or buy food? These are “effective”…….what exactly?

The limitations of Effective Speed are illustrated by this quote from Dr Tranter:

The higher trip speeds of cars do not save time; instead they encourage longer travel distances as the city spreads out and local shops, schools and services close.

Using travel time as the sole metric means the range of private benefits drivers get from their cars is ignored. The longer travel distances made possible by higher speeds mean drivers have a wider choice of destinations.

That might mean, for example, that they drive to better jobs, better dentists, better schools, or visit distant parents more frequently. Travel time is just a means to an end that, from the driver’s perspective, confers a private benefit and so is worth paying/working for (of course cars have social costs too, but that’s not what this discussion is about).

I’m not saying Effective Speed is “wrong”. I’m saying it doesn’t seem to be either particularly insightful or particularly useful.

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18 thoughts on “Is “Effective Speed” a useful concept?

  1. Last name First name

    Parker Alan. OAM
    Speed is controlled by speed limits that are enforced. This is why
    The European Parliament adopted a resolution in 2011 that “strongly recommends the `responsible authorities to introduce speed limits of 30 km/hr in all residential areas and on single lane roads in urban areas which have no separate cycle lanes “ This resolution is is part of a wide range of measures to halve Europe’s 31,000 annual road fatalities by 2020. (Kock Report 2011)

    The latest information from Europe is that a 30 kph limit on local roads and main roads in busy urban areas heavily used by walkers are much safer for al non-motorised users, motorised wheelchairs and electric bicycles. Compare this with the overall road safety record of the Netherlands and Australia shown on table 2.
    It is very clear that on the basis of kilometres ridden by bicycle in the Netherlands is still safer even though no one is compelled by law to wear a bicycle helmet. From the pedestrian fatality rates per 100,000 population for Australia and the Netherlands it is clear that since 1965 the Netherlands has been much safer for both pedestrians and cyclists. The Dutch government believes that the 30 kph limit is of great benefit to all non-motorised users”

    It is also assumed that riding a 25 km) speed limited electric bicycle “pedelec” is as safe as a bicycle given the existence of a low speed limit. This assumption is soundly based on data from selected bicycle friendly EU countries which have the following 2010 road death rates per 100,000 population: , Sweden 3.0, Netherlands 3.7, Japan 4.3, and Germany 4.7, Denmark 4.5, Switzerland 4.5 France 6.1. Australia’s death rate is higher (6.2) and the US death rate of 10.5 is even higher.
The European bicycle friendly countries are safer for all road users.

  2. Dylan Nicholson

    Oh and one more plus for cycling – the longer you do it the faster you get (I’ve shaved 10 minutes off my time from just 2 months ago). The reverse is probably true for driving (once you’ve figured out the best route) given our population is growing and the space available for roads isn’t…

  3. Dylan Nicholson

    And I’d still say the bugs you might pick on a train would do you more good than bad in the long run (build up that immune system!) compared to the long term damage being seated in your car and dealing with the stress of traffic for 30 or 60 minutes every day. Plus taking PT normally ensures you walk a reasonable amount each day.

  4. Steve777

    boscombe – you’re right about the coughing and sneezing. A bus or a railway carriage in winter is a mobile microbiological incubator, hermetically sealed, overheated (at 7:30 it’s 5 to 10 deg C on the outside, 22 to 24 in) and packed. On the odd occasions I need to used public transport these days, I avoid touching any surface in the carriage. It would be a good idea if commuters wore masks or gloves like they do in some Asian cities.

  5. boscombe

    Dylan, at last you’re on the right track. What we need is First Class carriages, where a ticket means a seat. But I dispute your assertion that PT is ‘better for you’ – one of the things I couldn’t bear about being crowded into a train carriage was the uncomfortable closeness of the many sick commuters: the coughing, sneezing, the stink of stale cigarettes and bad breath – what a great way to start the day.

    And as for cycles in Asian cities – yes I cycled everywhere in the years that I lived in China, only organisations had cars, not individuals. Now, all of my Chinese friends own cars. As soon as they can get cars, they do.

  6. Dylan Nicholson

    Driving’s not for everyone either, despite what people seem to think 🙂 But as I’ve said ad nauseum, go to almost any European or Asian city and see for yourself that there’s no reason cycling shouldn’t be the logical choice of transport for at least 25% of the population.

    Overcrowding on trains is definitely a problem, but as I said above, even having to stand on a train for 30 minutes is almost certainly better for you than driving a car for the same amount of time. But there’s no excuse for the level of overcrowding we have currently, considering how few users there are compared to many overseas networks (sure, trains in Tokyo or NY are often packed solid, but that’s probably inevitable at such high population densities). The line I’m on could easily run at twice the frequency it does now and there’d be seats available 90% of the time. I’d even pay more for a seat if such an option existed (as it is, Myki doesn’t even give you the option of paying for extra space, such as I use for my bike from time to time).

  7. Steve777

    Dylan, I’m sure you’re right about cycling, although it’s not for everyone. I’d as soon take some blankets and sheets down to the Parramatta Road and sleep on it as ride a bicycle on it. However, better cycling infrastructure (including showers and lockers at destinations) would make cycling more attractive to many.

    And you’re right about public transport. I noticed over a number of years how the time advantage in my commute by car from the North Shore to Parramatta (35 minutes versus 70 each way door to door in the mid 1990’s) was gradually whittled away by increasing congestion and parking restrictions. I would probably have switched to public transport had I worked there much longer. However, when I worked in the City my daily commute by train (35 minutes door to door each way) was dead time because the train was packed unless I left before 7:30. I would have driven if I could. But I didn’t have a hand-holdable mobile device in those days, so maybe the time would be more productive now.

    But in Sydney, even close to the City, unless your starting and finishing points are close to the direct route into the City or along the main Berowra to Penrith railways, public transport is barely faster than walking. In fact, I expect cyclic would be good for cross-suburban journeys if you’re willing to brave the traffic.

  8. Dylan Nicholson

    Except Steve, like I’ve said, I might well spend a few hours a week less in transit if I drove instead of cycled but the time I spend cycling is productive in an of itself, which would not be the case for driving. The same is true when I use PT, as I’m generally able to work for at least 80% of the time.
    For a very large number of people, I don’t even believe they *do* save actual transit time driving vs cycling (or taking P.T.). I would challenge anyone to make it from any suburb within ~7km of the city to any other such suburb in a car during peak hour faster than a moderately fit bicyclist could. And even if their whole journey is too far to make by bicycle, they could almost certainly carry the bike in the car part way and ride the rest (exactly what I did for many years).

  9. Steve777

    A ‘back’ of the envelope calculation: buy a car for $35,000 which is worth $5,000 after 10 years, so count $3,000 per annum. Other fixed costs (insurance, rego, regular servicing, etc) come to about $4,000 per annum, so that’s about $140 per week in the fixed costs of owning a car (assuming you’re not paying interest to a finance company). For someone on $60,000 a year, this is equivalent to about 5 hours per week. Actually, on that basis, owning and running a car does not look too bad if you can park for free or at low cost near your workplace and you’re saving more than 5 hours a week in commuting time.

    ‘Effective Speed’ doesn’t seem to support leaving the car at home, especially for the financially well off but time poor, especially when you factor in the other benefits of owning a car. Plus our cities and society are designed around universal car ownership, at least for those with money to spend. Most people have to drive and park at a supermarket so they choose to fill the boot once a week. Most don’t have the choice of a daily walk to a corner shop with a string bag.

    The push for a move away from the car needs to concentrate and the social costs, as well as making the alternatives more attractive and viable to more people.

  10. Alan Davies


    In such cases it makes a lot of sense to compare the benefits of time saving verses the cost of buying a car and paying high fixed costs for registration, insurance, servicing every 6 months and so on.

    Yes, that sort of comparison makes a lot of sense. But that’s because it isn’t Effective Speed (according to the linked article, Effective Speed is about hours worked vs hours travelled in-vehicle).

  11. Steve777

    I think that the concept of ‘effective speed’ has some validity although it doesn’t tell the full story. It would be especially relevant if someone was purchasing a car for the main purpose of commuting (e.g. a second car for a two-job household). In such cases it makes a lot of sense to compare the benefits of time saving verses the cost of buying a car and paying high fixed costs for registration, insurance, servicing every 6 months and so on. It would be less relevant to someone who was determined to own a car anyway, regardless of commuting needs. In such cases, ‘sunk costs’ would be a major determinant, i.e. why have a car with it’s initial outlay and high fixed costs in the garage and take public transport?

  12. Dylan Nicholson

    boscombe, actually, riding a bike 15km (or more) home in the dark, especially after a few beers, is one of the best feelings in the world!

    As for your points, all true, but there’s still a huge number of motorists on the road for whom alternative modes of transport would make much sense, providing of course a) our PT was comfortable, reliable, frequent and had consistent high availability and b) there was good bicycling infrastructure and a culture of promoting and accepting cycling as a sensible form of transport.
    I’d argue the cost of addressing these in most Australian cities would pay for itself many times over.
    And it *should* be easier for people to live closer to where they work – but that’s a much harder problem to fix, as while housing affordability/availability is part of it, it’s also the fact that in a given household, people work in very different locations and are often more afraid of/resistant to changing jobs than they really need to be.

  13. boscombe

    Completely agree, Alan. I read that article and couldn’t see the sense of it. Everyone knows about the wonderful benefits of cycling or using public transport, but most people would have to be forced to give up using cars, and for good reasons.

    I gave up years of commuting by train when the crowding became unbearable. I tried buses and found them unreliable, uncomfortable and very time consuming. Commuting by car saves me at least an hour a day, which I use for a bit of a run and swim at the beach. I stop on the way home from work to pick up shopping or dry-cleaning, or see a movie … many things. I take my lunch to work in several glass (don’t like plastic) containers, and on the way listen to CDs if I don’t like the radio. Should be listening to learning Mandarin CDs but am at present hugely enjoying tango CDs picked up recently in Buenos Aires.

    A colleague brings her harp into work on Thursdays, because she goes off to her harp lesson at lunchtime. She’s even older than I am and might have difficulty managing the harp on a bike, or on and off the bus.

    Perhaps like many other people I can’t be sure when my work day will end … I thought today it would be six, but it was nearer seven, and could have been ten – I can imagine my public transport options outside peak hour, or the joys of riding a bike home 15 kms in the dark.

    Another article on The Conversation recently suggested people move closer to work and walk or cycle. Apart from the unaffordability, that assumes that people only go to work. I go to the beach every morning, and in summer, go after work as well …. that’s why I live near the beach!

  14. suburbanite

    Well then it’s just as well your here to keep everyone honest, but in my defence I said it was useful, not that it is without flaws. Making a fair comparison of transport modes seems to me impossible because there is no unbiased reference point (or urban model) from which to begin the comparison. Most discussion start with an acceptance of the car dominated status quo and work from there. Within a couple of generations cities have been remodelled around a relatively new and completely unsustainable form of transport and then planners make unfavourably comparisons with everything else against that.

  15. Alan Davies

    suburbanite #3:

    Any metric that challenges the normalisation of car dependence is useful as far as I’m concerned.

    That’s the sort of argument politicians of all colours used to justify their various and often nefarious ends! Knowingly using a specious argument is never a good idea in my view because (a) it’s ethically dubious and (b) it’s tactically risky – it might come back and bite you and your cause on the bum. There are plenty of good pro-PT and anti-car arguments out there without having to make up specious ones.

  16. suburbanite

    “Using travel time as the sole metric means the range of private benefits drivers get from their cars is ignored. The longer travel distances made possible by higher speeds mean drivers have a wider choice of destinations.”

    The range of private benefits of car ownership hardly needs reinforcement – the whole of society panders to car use and a range of illusory benefits are repeated ad nauseam by advertising.

    Any metric that challenges the normalisation of car dependence is useful as far as I’m concerned. There is a complete imbalance in any policy discussion about transport in favour of exaggerating the benefits of cars and hiding the negative impacts.

  17. Dylan Nicholson

    I can’t say I’ve ever had a problem carrying spare underwear while cycling!
    But yes, I agree it’s not a terribly meaningful concept – to me the huge contrast between driving and other modes of transport is that single-occupant driving through traffic is almost entirely “dead time”: it’s not restful, you can’t use it for any tasks that require much concentration, and it certainly doesn’t help maintain your health and fitness (in fact, as per nearly all sedentary activities, quite the opposite). The time you spend in almost every other form of transport can and should be productive in its own right, whether it’s because you can read or work on PT, or because of the physical benefits you get from walking/cycling. Even being crammed into a packed train with no room to move at least avoids the negative health impacts of long periods of sitting still (and is almost certainly less stressful than navigating through traffic). Seriously, in most cases the ONLY reason for using a car for me is if you have a lot of stuff to carry (e.g. a whole week’s groceries, and/or multiple kids), or if the weather is truly abysmal. That is of course providing you can afford to live somewhere where you have multiple good alternative transport options – and the fact that so many can’t (or don’t) is arguably one of the greatest failures of urban planning in this country.

  18. Last name First name

    Parker Alan • OAM

    Ivan Illich expanded on this in his book this narrow viewpoint. Indeed, these biases are ignore a basic human right. It is argued that due to unsustainable vehicle ownership and population trends in the developing world, that many of the world’s child cyclists, are at risk on their rapidly expanding road systems. Therefore the June 2012 Velo-city global conference IN Toronto calls for the UN to enshrine the“Child Rights to Cycle” for Children should be endorsed by this conference. Paul Tranter attended that conference and the “Childs Rights to Cycle” issue was being supported by him and the entire conference representing every national bicycle user group and all the experienced traffic management and bicycle Planners.

    Alan and your fellow planner In Melbourne do not recognise the “Childs Rights to Cycle”. Dutch, Swedish, Danish bicycle planner acted on it for a long time. This is why they have 30 km/hr speed limits on residential streets and 50 km/hr limits on main roads with bike lanes. And well thought fine mesh bikeway plans. You academics do not get it do you. Sorry to be so but the Paul Tranters are the good guys

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