This previous post considered wider socio-economic factors which might shape the development/deployment of transport technologies, namely 1) denser cities, 2) policy settings, and 3) demographics. In this post I now discuss some more specific issues that are relevant to transport technologies, specifically:
- Economies of density
- Costs: Fixed versus variable
- Complements versus substitutes
- Conclusions: The Spruce Moose?
The takeaway message from this post is that the future is complex and uncertain. D’uh … read on for enlightenment!
1. Economies of density
The Prime Minister’s recent speech, in which he announced funding for the City Rail Link and the East-West Link, is an example of how policy settings can respond to wider socio-economic factors, such as population growth. Auckland’s rapid growth means that public investment in underground passenger rail stacks up more now than it perhaps has done in the past. As a result changed, Auckland’s transport network is set to change in a rather profound way.
Why has Auckland’s growth helped make the case for the CRL? Well, passenger rail has relatively high fixed costs. This in turn means that passenger rail experiences so-called economies of scale (or more accurately density). The phrase “economies of density” is used to describe situations where marginal costs are below average costs. This means that average costs fall as demand increases. Fixed costs like rolling stock and train stations all contribute economies of density in passenger rail.
Last week saw another example of “economies of density” in the context of New Zealand’s transport system, although this time the investment originates with the private sector. Emirates announced that – from this March – they will begin direct flights between Auckland and Dubai (NB: Apparently Qatar Airways is considering similar moves). Direct flights to Dubai will shave approximately 3 hours off travel-times between New Zealand and a number of destinations in the Middle East and Africa.
Economies of density lead to virtuous/vicious cycles: Higher demand begets lower costs, which begets higher demand etc (and vice versa). That’s why they are sometimes called “positive feedback loops”. Domestic air travel in New Zealand provides a nice example of virtuous cycles at work. Here, a combination of falling fuel costs, higher visitor numbers, larger and more efficient planes, and competition has seen airfares fall (NB: I’m waiting on updated inflation data before making a more definitive statement). Many transport technologies, especially those where passengers share vehicles and/or facilities, tend to experience economies of density.
Private vehicles also experience economies of density to some degree. High levels of car ownership, for example, makes it easier to find a petrol station when you need one. The key difference between private vehicles and other transport technologies, however, is the degree to which road networks experience congestion. Beyond critical levels of demand, traffic congestion increases rapidly, i.e. congestion is a convex (upwards sloping) function. Congestion externalities are an example of dis-economies of density, and it’s one that is apparent in most cities of Auckland’s size and larger.
Congestion externalities are also an issue that things like driverless and/or electric vehicles do not resolve. Road pricing does solve congestion, although this is achieved by suppressing demand. So when people argue that electric and/or driverless cars will reduce demand for PT I’m somewhat sceptical, because these technologies don’t seem to change the fundamental dis-economies of scale that afflict urban road networks.
And when one thinks of the growth that Auckland will experience over the next 20 years, then economies of density are actually rather important. Perhaps more important than new technologies themselves …
2. Costs: Fixed versus variable costs
Our previous discussion noted that economies of density/scale arise in the presence of fixed costs. In this section I want to distinguish more carefully between fixed and variable costs. One useful way to think about transport costs is using a matrix which has “fixed/variable” versus “private/public” dimensions (NB: The latter is not relevant to this discussion, but can be for discussions of transport pricing more generally).
Of course, such distinctions involve some arbitrary judgements. Parking for example, is both a private and a public cost. I’ve categorised it as “public” simply because a proportion of parking costs are subsidised by society. Despite the need for such judgements, I think this type of cost matrix is quite useful for classifying costs and subsequently analysing how changes in transport technologies (or policy settings for that matter) might impact on demand.
Using this framework (and a bunch of heroic assumptions) I have constructed the following graph to illustrate how the costs of cars compares to taxis and public transport, and how costs vary with distance measured in kilometres travelled per annum. PT fares are capped at the price of 12 monthly passes at $220 per month).
Here we see that cars become cheaper than taxis for people who are travelling more than 2,500 kilometres per year. Of course, the orange line is just one possible instance of the cost curve for cars. Depending on their preferences and circumstances, some people may opt to buy a cheaper car with higher operating costs, which would reduce the intercept but bump up the slope of the orange line. Nevertheless, the general point remains: For people who travel a lot, owning your own car makes more sense than using taxis.
Now consider a future scenario where electric driverless vehicles (“robot cars” for short) are available. How might they impact on these cost curves? Well, let’s assume robot cars cost 50% more than conventional cars; are 50% cheaper to park; and cost 25% less per kilometre to operate/maintain than conventional cars. When robot cars are used for taxis, they remove the need for a driver and increase higher utilisation. For the sake of the argument, let’s assume that the cost of using taxis drops by 50% with the advent of robot cars.
Under these assumptions, the cost curves presented above can be re-calculated as follows.
In this scenario taxis suddenly become cheaper than private cars for people who travel less than 10,000 kilometres per annum. By way of comparison, that’s slightly more than the average New Zealander travels per year. By pushing up fixed costs but reducing variable costs, robot cars seem to dramatically increase the scope for cheap taxi services to meet the demand for car travel for a wider range of households.
So consider this “what if” scenario: What if the primary impact of robot cars was to reduce the cost of taxis? In such a scenario would we need more or less PT? This leads me nicely onto the next topic …
3. Complements versus substitutes: A or B versus A & B?
When a new transport technology hits the market, one of the key questions we should seek to answer is whether it will complement or substitute existing technologies. The answer is not always obvious, but it is always important.
To provide an example, consider whether taxis increase or decrease demand for public transport. Many people think taxi’s compete with public transport, i.e. the two are substitutes. Rodney Hide, for example, had this to say on the matter (source; emphasis added):
[Uber is] … a whole new way of doing business. It disempowers bureaucrats and puts customers and drivers in charge. I love it. The public transport of the future won’t be clapped-out trains but driverless cars and Uber. It may happen much quicker than we now can possibly imagine. We won’t own a car. A driverless car is always just a minute away, ready to whisk us to our destination.
According to U.S. researchers, however, taxis are complements for public transport. This article provides a nice synopsis of relevant issues, while more detailed analysis is available here. The last report identifies “primary factors” for taxi demands, including 1) the number of workers commuting by subway and 2) the number of households that don’t own vehicles. Of course, places like New York have some attributes which are – for better or worse – not relevant to the New Zealand context …
Given that Auckland doesn’t have the density or subway system which exists in NYC, could Rodney be correct with his crystal ball-gazing? The answer, I think, is both “yes and no”. More specifically, taxis will compete with public transport in some places, while complementing it in others.
I think this article puts the distinction rather nicely when it says:
It is likely that these [taxi] services will just exacerbate the differences that already exist in the quality of public transit in different areas. The localities that invested and ran their systems well won’t be as impacted. In the areas where frustration is higher, the problems will surely become worse when revenues and ridership decline. And the biases and history that impact why certain systems are the way they are will become more apparent.
The complements versus substitutes issue is relevant to many debates about new transport technologies. Some people seem convinced not only that driverless cars are imminent, but that they will drag people away from PT. I’m personally not so sure.
Conclusions: “The Spruce Moose”?
One of my favourite Simpsons episodes starts with Mr Burns opening a casino. At the end of the episode, when the whole sordid venture is crashing down, an increasingly erratic Mr Burns pulls a gun on his ol’ mate Smithers and orders him to get into the model bi-plane affectionately known as the “Spruce Moose”.
While hilarious, the behaviour of Mr Burns is not something we should emulate when it comes to transport policy. History is littered with unfortunate examples of politicians picking winners well in advance of demand. Indeed, such attitudes gave us 50 years of motorway building in Auckland, replete with well-documented examples of optimism bias and strategic misrepresentation. My point? Let’s not hold a proverbial gun to our own heads and over-commit to any particular kind of transport technology. Instead, let’s embrace the transport technologies we have, and be passionate about using them more efficiently, while keeping tabs on new transport technologies as they evolve.
There is no doubt that we live in exciting times: New Zealand is growing and seems to be experiencing economies of density, at least in the transport sector. Costs of air travel are falling, while other technologies, such as passenger rail, are more viable than they have perhaps been in the past. Robot cars and trucks seem likely to emerge onto the scene at some point, helping our car fleet to become smaller, quieter, cleaner, and generally more efficient than it is currently.
Meanwhile, rapid developments in telecommunications (which I intend to discuss in a later post) are changing the way that goods and services are delivered. This change is occurring at astounding speeds and in amazing ways. In a few years Uber has grown to become one of the world’s most valuable transport companies. In Europe, a start-up called “Blah blah car” has raised hundreds of millions in venture capital to expand its business, one which is already moving millions of people around the continent at very affordable prices. I can book any one of 5 trips from Amsterdam to Brussels tomorrow for about 10 Euro.
In such a dynamic and rapidly changing environment it’s hard to know what to do. And that’s kind of the point: There’s a risk that we over-adjust to new technologies, just like the motorway builders did in Auckland 50 years ago. What I would do, however, is ask some hard questions “around the edges” of what we are currently doing. And perhaps consider delaying some projects slightly in light of the uncertainty.
Indeed, when it comes to the CRL, my main criticism of the National Government’s requirements for accelerating funding was that similar conditions were not also attached to other large transport projects. Appropriately specified triggers would seem to be useful adjunct to existing benefit-cost analysis and provide a more precise understanding of when work on a particular project should go ahead (NB: Of course there are other factors to consider, such as interest rates).
In an upcoming post I will talk more about emerging technologies for non-car transport modes; that stuff is so exciting it deserves its own post.