Up and Out: The Future of Travel Demand and Where We Live
Adapting the Built Environment
Reduce, Reuse, Bicycle
Accelerating the End of Traffic via Pricing
Post-script 1: What Happened to Traffic?
Post-script 2: Now extinct: the Traditional Transport Engineer
In this book we propose the welcome notion that traffic—as most people have come to know it—is ending and why. We depict a transport context in most communities where new opportunities are created by the collision of slow, medium, and fast moving technologies. We then unfold a framework to think more broadly about concepts of transport and accessibility. In this framework, transport systems are being augmented with a range of information technologies; it invokes fresh flows of goods and information. We discuss large scale trends that are revolutionizing the transport landscape: electrification, automation, the sharing economy, and big data. Based on all of this, the final chapters offer strategies to shape the future of infrastructure needs and priorities.
We aim for a quick read—and to encourage you and other readers to think outside your immediate realm. By the end of this book (today, if you so choose) you will appreciate the changing times in which you live. You will hopefully appreciate what is new about transport discussions and how definitions of accessibility are being reframed. You will be provided with new ways of thinking about the planning of transport infrastructure that coincide with this changing landscape. Even if transport is not your bailiwick, we like to think there is something interesting for you here. We aim to share new perspectives and reframe debates about the future of transport in cities.
Another key point was that states (and the federal government) should probably spend less money on building new roads and more money on maintaining existing roads. Economists have argued that more states should probably be doing this anyway — this Brookings Institution paper by Matthew Kahn and David Levinson makes the most comprehensive case. But the argument gets even stronger if vehicle travel is going to grow more slowly or plateau in the future.
What’s clear is that it doesn’t make much sense for states to keep planning around the idea that driving will grow at 20th century rates forever. Those predictions have been utterly wrong for nearly a decade now — and sticking with them could mean wasting billions on unnecessary roads and highways.
Just as we draw the life-cycle of technologies as a logistic function or S-curve, presumably there is an S-curve for the accumulation of knowledge.
In principle, if the universe were finite, there would be a sum total of all possible knowledge. If there were a fundamental particle, this would be something like the position, velocity, acceleration (in all dimensions, with all possible moments, in a physics well-beyond Newton’s) of each particle now, and its entire history – since while the future may be determine from the present, there may be multiple pasts which could generate this present.
It is possible this could be reduced with some intelligent compression algorithm, for instance knowing the fundamental equations, the appropriate coefficients, and the initial state of the universe. I am nevertheless doubtful that with a complete description of the initial state of the universe we could actually explain and reproduce the production of this blog post.
Suffice it to say this information would require something more than universe size to store it, since the universe stores its present state, but perhaps not it’s past states (i.e. it is Markovian).
The knowledge we actually have is a very, very, small subset of this, perhaps only 1 googolplexth of all knowledge (if that much). (If a hundredth is 1 / 100, a googolplexth is 1 / a googolplex).
We are in no danger of discovering all that needs to be discovered. We are still in the early, “birthing” stages of knowledge acquisition.
Get back to the knowledge-mines ye academics, there is much to do.
In the US, we have seen a great struggle play out in the twentieth century between what David Jones calls Mass Motorization and Mass Transit . The conflict between the modes continues to this day, and has become a morality play in the culture wars. While they mostly serve different markets, they compete for users, and roadspace, and funding, and the hearts and minds of travelers. They are competing on old turf though, as the graph shows, both modes appear to be in decline, transit for decades, the decline of the auto-highway-system is just beginning.
To develop a metaphor Kevin Krizek and I used in Planning for Place and Plexus, the US spent from the late 1880s through the early 1920s climbing Mount Transit. Transit was the most important mode of travel (after walking) in large and medium-sized US cities. The rise of transit was enabled by the electric streetcar, itself a product of electricity, harnessed by Edison and others, and the modern railroad, developed beginning in 1825 with the Stephenson’s steam-powered Stockton and Darlington Railway. Transit peaked in the US in the 1920s, but for a spike during World War II when oil and rubber were rationed, crimping the US of the automobile. From the end of the War forward, it began a steady decline from which it has not really recovered. Despite the so-called resurgence of transit, and receiving about a quarter of federal surface transportation expenditures, transit trips per capita remain below 1990 levels.
The US spent almost the entire twentieth century climbing Mount Auto. From the 1920s onward, the automobile was the dominant mode of travel for Americans, accumulating more miles per capita than other modes. While the Great Depression slowed the auto’s growth, it did not result in decline. There was a brief downturn during World War II, and a couple of hiccups in the steady rise of mileage due to oil shocks in the 1970s and early 1980s (Yom Kippur War through the Iranian Revolution, before oil deregulation), early 1990s (Gulf War), and early 2000s (9/11). But the later 2000s and 2010s have seen a sharp downturn in auto use per capita. This drop is greater than the drop during World War II in absolute terms (though the War saw a drop of 23% off the pre-war peak, and the 2012 drop is 7% below 2005). It is complemented by an apparent downturn in total miles of paved roads.
In The Transportation Experience, William Garrison and I trace the policy, planning, and deployment of transportation technologies across time. Both the auto and transit follow the classic lifecycle model or S-curve of birth, growth, maturity, and decline. (One hesitates to say “death”, since so few technologies actually disappear, fixed route streetcars are still with us for instance. Kevin Kelly has found that no technologies actually vanish, though obviously they diminish in importance). The S-curve allows us to mathematically approximate the process of growth and decline of technologies. It is in many ways natural (if we start with 0 vehicle kilometers traveled by car per capita in 1900, surely the number has to go through 5000 VKT before it reaches 10000 VKT, and 10000 before 15000. One million people must own a car before two million can. Similarly, technologies don’t disappear overnight (although transit really came pretty close). These are long gradual processes, and the occur over many technologies which see growth and decline. Transportation is among the slowest of these technologies, as fixed infrastructure is expensive to build and long-lasting.
The growth curves reasonably fit the data for total system size or total system use for a number of technologies in retrospect. A collection of such curves, and descriptions of the development of the associated technologies can be found at the Transportation Deployment Casebook, which is the result of student projects for a few years in my Transportation Policy course.
The difficulty is to use such curves in prediction. There are some observations though, the left and right sides of the curve (from the inflection point, where the rate of growth changes from increasing to decreasing) are approximately the same amount of time. (So it takes about as long to go from 10 to 50% of the final market size as it does to go from 50 to 90% of final market size.)
A key issue is the determination of how large will the system get at its maximum? It depends on the system. For instance if we are modeling the number of US states that will adopt some policy, the maximum is 50 (unless the US adds states). If we are modeling the percentage of cars that will have some advanced technology, and we believe it will become universal, then we can say 100%. But if we are modeling a continuous number, rather than a share, it is harder. What is the maximum number of kilometers people will travel in a year? What is the maximum number of trips? We can make guesses; we can even make informed guesses, but we can never know for sure until after the fact. However, if the rate of growth has slowed (we are on the right half of the S-curve), we can make a much better guess than if growth is increasing at an increasing rate (the left half of the S-curve).
Is the decline in auto permanent, like what happened to fixed route transit services in the US (which is well below one-fifth of its previous importance), or just a brief digression from the steady march of increasing per capita vehicle travel that has been following the same drum almost continuously from 1910 to 2000? History will tell us for sure, but the evidence for “Peak Travel” has been mounting. This does not mean there will never be a year in which auto travel again rises. The economy and gas prices still fluctuate, and a boom year with low gas prices following a recession with high gas prices might very well temporarily bump traffic upward, but that is really short-term noise. In the absence of external events (technological shifts, demographic shifts, social shifts), the curve appears to have peaked. But over the longer term, a significant technological shift could profoundly change how people use the automobile. If there were only one possible significant technological or social shift, this might be predictable, but there are numerous technological and social shifts in play.
There are many reasons people are not driving more, but “saturation” satisfies Occam’s Razor. There is only so much time in the day. For a worker who spends at least 8 hours at the office and 8 hours asleep, how much time is reasonable to actually spend traveling as opposed to the other things that comprise life. Each additional minute traveling is one less minute doing something else. The literature on the travel time budget is rich, and while people do want some separation between their home and work lives, most people do not want to spend too much time (say more than 90 minutes per day) traveling on a regular basis. The travel speeds of current technologies limit distance.
Similarly, there are a variety of complementary hypotheses as to why people are driving shorter distances, some of the important ones include:
Price of fuel – higher energy costs diminish travel
Size of the workforce – fewer people working leads to fewer work trips (due to both unemployment and labor force participation)
Telework – people working at home for the day leads to fewer work trips (but more non work trips)
Online shopping – buying over the internet at home decreases shop trips
Virtual connectivity – connecting with friends at home can substitute for visiting
Obviously different demographic sectors do these things in different amounts. Just as your grandparents may still receive a physical issue of the newspaper while you read online, young people are more likely to be early adopters than their parents and grand-parents. And the habits formed while young may very well persist over time.
These last three reasons for traveling less by auto (and overall) are due to information and communications technologies substituting for travel. But these are all non-transportation reasons.
There are active transportation modes, like walking and biking, which work well for short trips, and certainly have niches they can grow into if land development intensifies and people reorganize their lives to enable them (for instance, I am one of the 7% of Minneapolitans who walk to work, the numbers are much lower outside core cities, and nationally (3%)).
There are a slew of “new mobility options” which use information technologies to allow travel without owning an automobile, but are not yet visible in the transportation statistics. These include peer-to-peer taxi and ridesharing services, dynamic real-time rental cars, and the like. While these are useful in their niches, they are not cost-effective to be the main transportation mode for the vast majority of the population with the given technology. But they are supplements when the main mode doesn’t solve the job to be done.
Technologies allow people to do more of the same, and they allow people to do new things. It is easier to predict more of the same than new things.
I believe the more important technological changes over the next few decades are those associated with autonomous vehicles. Cars that drive themselves change how people use them. First in “the more of the same” category, we might see more travel.
Generally as the cost of travel declines, travel increases. Since fully driverless cars make it easier to drive (by reducing the cognitive burden on the driver) the initial effect would be that people would travel farther, to places they are less familiar with, and move to places farther from their place of work, to get more real estate for the dollar. Today’s commuter rail passengers travel farther (and longer) than auto users, and autonomous vehicles, where the passenger can do something else while traveling are more like commuter rails than are today’s cars
Such cars also can deposit drivers in front of buildings and park themselves, reducing the amount of time that drivers spend parking and accessing and egressing their cars, which would naturally lead to longer distances.
Third, such vehicles are likely to be safe at higher speeds, since humans won’t be driving, which will also lead to longer distances in the same travel time.
Further such vehicles expand mobility for those who are now restricted (the young, the disabled, and so on).
However such cars also make the so-called new mobility options much more useful in cities. Instead of owning a car, renting on demand becomes much more viable. The right-sized car can in principle be summoned at any time. And if a driver is paying by the minute when the car is used, instead of paying for a car loan or lease by the month (whether or not she uses it), the incentive structure the driver faces changes. Travel will be less frequent and more thoughtful. The daily pattern of transit for routine trips and a “nextcar” for special trips becomes feasible. The lack of nextcar options now pushes people to owning vehicles, and once they own a vehicle, they are going to use it. This lifestyle model works in cities, where transit can be a mainstay transportation mode, and nextcars are conveniently located.
It works less well in the suburbs, exurbs, and rural areas, where the baseline transportation mode cannot be as expensive on a per-trip basis as the nextcar’s rental model requires, but the density is not high enough to support fixed route transit on most corridors.
Obtaining better capital utilization out of our surface transportation fleet (like the airlines have achieved with planes that are in motion as much as possible) through nextcar like vehicles will reduce the lifespan of cars by using fewer vehicles more intensively, and wearing them out sooner. Thus nextcars will on average be newer than today’s fleet. As technology continues to advance with greater rapidity, this becomes increasingly important. The difference between a 2030 and 2020 model likely will be far greater than the difference between a 1970 and 1960 model car.
These are gradual processes. The rapid change in information technology can inform us of the direction of changes in transportation, but the pace cannot be replicated. The technologies are different. Building roads or rails have socio-spatial implications that laying fiber optic cables or constructing cell phone towers do not. The lifespan of a car (15-20 years) far exceeds that of a smart phone (about 3 years), so the technology people possess lags far behind the technology that is possible.
The mountain analogy implies society cannot climb to the peak of the next technology in the same market niche (for instance, serving daily transportation needs) until it climbs down the first. One can imagine a technological helicopter or zip line, or leaping off the peak (abandoning existing function technology, rather than just depreciating it over time) to accelerate transformation, but such sudden changes are rarely wise and even less politically acceptable, with entrenched interests having accumulated power desirous of maintaining (or expanding) the status quo.
If the Future of Transportation does not involve more information technology and more automation, I will be both disappointed and surprised. But the exact shape of what comes next is hard to say. In the 1980s, we had a vision of a future of telecommunications and information that was something like what the internet came to be, all the world’s information at your fingertips. But few foresaw that it would be supported by online advertising. The idea that a collaboratively built online encyclopedia would displace Britannica, and be of the world’s biggest websites, or that an online bookstore (a bookstore!) would be on a trajectory to become the world’s largest retailer were all unpredicted and unpredictable. So it is with transportation in 2014.
“It might seem a rather arbitrary milestone to take note of, the total length of our roads. After all, social science gives us a multitude of metrics seemingly more suited to measuring and quantifying our social states. The General Social Survey every two years releases volumes of data tracked rigorously across decades on political attitudes and lifestyle decisions. The Bureau of Labor Statistics monthly releases job reports that set the conventional wisdom as to the strength of the economy, with its accompanying political credits or demerits. The Census Bureau, decennially counts every person in the country, along with a host of distinguishing demographic data. Why, then, pay attention to the pavement?
Because our roads are the received and transformed legacy of the American Frontier. As Patrick Deneen recounted a couple months back, Frederick Jackson Turner’s landmark study ‘The Significance of the Frontier in American History’ noted the official close of the frontier as recorded by the 1890 Census report, when there was no further line to be pushed out into by isolated settlement. From then on, the American adventure spirit that had always held the possibility of lighting out into new discovery had to turn around, and take stock of the suddenly limited land around it. Rail would be laid, and roads built, crawling the wilderness with pathways of civilization. America went from an outward-facing nation to an inward-facing one, exchanging unlimited bounty for density and connectedness. Yet the free spirit of the frontier was not altogether lost.
As Ari Schulman wrote in his excellent 2011 New Atlantis essay ‘GPS and the End of the Road,’ ‘Even once the Americas had been crisscrossed with rails and paved roads, a new age of discovery was opened—the age of personal discovery celebrated in the mythology of Kerouac and the open road.’ As the roads grew before us, a car provided an escape to, if not the wild, at least the novel and the new. New people, new towns, localities being newly opened up or communities newly connected allowed us to learn from this sprawling country of ours, and learn about ourselves through their pursuit.
It takes on a different tinge, though, when you know the road is shrinking back towards you. Mobility allowed us to escape the strictures of place, as Deneen described, attenuating our connections to home as we built new ones around the nation. Shrinking, though, can make for a very different kind of smallness than that championed by the localists mobility left behind. As the open road recedes, how will the restless American spirit take to density?”
I really like the analogy of Peak Roads to the End of the Frontier.
The new version of The Transportation Experience describes the history of transportation across several five to six decade long waves. While the periods are straightforward (though somewhat arbitrary, as would be any periodization of social trends), there is some subjectivity in the dominant technology with which to characterize them. Certainly the first period is an age of Steam, and the second period is the dawning of electrification (the birth of the streetcar, as well as electric utilities, the telegraph and telephone), while the third sees the rise of the Internal Combustion Engine and motorization in all its forms. The fourth wave does not have as its center a new propulsion technology, but instead is more about reorganization. In freight this is the logistics (containerization) revolution. In roads, it sees the deployment of limited access road networks, aiding freight logistics of course, but also reshaping cities. It also sees the beginnings of deregulation (airlines, railroads, trucking, energy, telecommunications) and continuance of rationalization and consolidation in the mature modes.
Wave 1: 1790-1851: Steam
Wave 2: 1844-1896: Electrification
Wave 3: 1890-1950: Motorization
Wave 4: 1939-1991: Logistics
Wave 5: “Modern” Times: ____
Now in modern (or should we say “post-modern”) times (in the developed countries) the freeways are built and we may have peak car and peak road, if not peak travel overall.
Everything that used to be “modern” is now old. What comes after the “modern” is “post-modern.”
So instead of describing what post-modern transportation should be, let’s describe what it is. It seems the post-modern era (like eras before it) is about doing the same things more efficiently (i.e with less input resources of time, money, energy, safety, clean air) (which are easy to spot), as well as some new things (which are harder). Perhaps most importantly, it is about doing fewer things with transportation when transportation is not required. This doesn’t mean no transportation of course, so long as we avoid the Matrix, we will need to move physically not at least some of the time. But if we use less transportation, we also use transportation differently. Renting (sharing) becomes a more viable option. Riding transit occasionally rather than storing a car always is more cost-effective. Thus, the price we face begins to be a marginal cost (for vehicle ownership) rather than an average cost.
The things which transportation does are connect people and places. We often say transport is a derived demand, meaning we travel to do something else, not for the sake of travel. So doing the same thing does not necessarily mean using the same modes in the same amount.
There are many trends in US surface transportation, some notable ones are listed below:
We substitute telecommunications for some out-of-home activities like working or shopping.
Transit ridership in the US is increasing (though nowhere near its 1946 peak), Miles of rail transit network is steadily increasing, Transit capital spending is increasing, Buses still carry more passengers than rail, but the gap is narrowing (as more rail is built)
Mobile internet enabled mobility options like Uber and Lyft exist and are growing rapidly.
Interstate toll road mileage is up about 17% in the past decade, non-interstate is up 12%.
So from my perspective these longer-term (decadal) trends are in the right direction. Still, the outcomes are not where we want them to be (since the logical (cost-independent) goals are Zero Emissions, Zero Deaths, Zero Delay, Zero Wear and Tear, etc.). The trends may not be moving fast enough. Certainly not each decision is optimal. These trends are the collective product of government decision-making, along with the decisions of hundreds of millions of travelers, vehicle makers, entrepreneurs, and so on. Trends that are favorable to transportation may be unfavorable to the economy (we are in part traveling less because fewer people are employed), but that is not the whole story. If we can make transportation more productive (do more with less), we can use those extra resources to do something we value more highly.
Unpaved mileage has been generally declining for years, as unpaved roads were paved. But paved miles (and the total) have generally been increasing, until between 2008 and 2011 that is. Some of this is likely to be statistical noise (either reporting errors on the part of one or a few states, some changes in definitions), but some of it is real, as states and localities begin to gravelize. We see that about half of the decline in paved roads is compensated for by an increase in unpaved roads.
In the railroad sector, miles of track peaked around 1920, though freight traffic continued to increase, and there is more traffic and especially more productivity (traffic per worker, traffic per mile) today then ever before. Using that as a model suggests the issues are complex.
Clearly we have overbuilt much of the road network. We can think about a number peaks, which will not likely occur simultaneously:
Peak Freeway Centerline Miles
Peak Freeway Lane Miles
Peak Freeway Surface Area
Peak Non-Freeway Centerline Miles
Peak Non-Freeway Lane Miles
Peak Paved Surface Area
Lane miles may continue to increase well after centerline miles have decreased, as some roads are abandoned (faster than new routes are built), and others continue to be widened.
The processes that govern this, in order of the immediate significance, I posit as follow:
Rural depaving (gravelization)
Removing urban freeways
Complete streets/road diets
Skinny cars and automation
While freeway centerline miles are almost done, and overall centerline miles quite possibly are done, lane miles still have a lot of potential capacity. The transportation-industrial complex doesn’t care much whether it is paving a new link or widening an existing link (though clearly some prefer one over the other). It will be saddened and disheartened to see total capacity decreasing however.
(re trend 1. [new federalism]) I think this trend is more relevant to the US than Australia at this time, although Tony Abbott’s promise that a government led by him wouldn’t fund urban public transport might herald a structural change.
(re trend 2.) The high cost and political difficulty of retro-fitting transport infrastructure in dense urban areas means the emphasis must necessarily shift to making existing infrastructure work better e.g. by road pricing; better networking; giving road space to other modes.
(re trend 3.) The fuel excise in Australia isn’t hypothecated to roads, but it’s a very big revenue source. It brought in $15.5 billion in 2008/09 ($10 billion net). It would’ve been much more if indexation hadn’t been removed in 2001.
(re trend 7.) I expect car-sharing (actually it’s more like car rental – riding a train is sharing) will grow, but still only account for a microscopic share of total travel. Widespread use of autonomous cars is the only way I see it possibly having a significant role.
(re trend 8.) The dominant view among researchers is electronic communications increase the demand for face-to-face contact – and hence increase the demand for travel – rather than reduce it.
(re trend 9.) What Prof Levinson calls consumer sovereignty also applies in other areas like specialist health care.
(re trend 10.) I think the interesting trend Prof Levinson identifies is crowd-sourcing information from travellers in real-time via their smartphones and GPS e.g. Tom Tom congestion index.
(re trend 12) The primary change here is people study longer and so enter the workforce later; and retire (or go part-time) earlier.
(re trend 13) The likely timing is arguable, but when they get critical mass autonomous vehicles will likely constitute an enormous change to transport and land use.
Davies notes in a footnote: “There seems to be an inconsistency here – [excluding road pricing] there are even fewer implementations of autonomous cars. He also confines himself to technology trends, yet changes in working hours don’t fit that description well”
First: I acknowledge that road pricing exists more now than 40 years ago (a few urban implementations of cordons, a few HOT lanes, some time of day pricing on toll roads, bridges, and tunnels), so perhaps it is unfair to exclude, but its growth rate is really really slow. Toll shares of US transport revenue hovers in the 5-6% territory and isn’t changing much. So, to my disappointment, I don’t think it is a trend shaping transportation. I have become a pessimist on the actual adoption of road pricing in a significant way on existing facilities, aside from HOT lanes. While I can foresee an Odometer tax replacing the gas tax at some point, I am doubtful there will be widespread peak discounting, or that it will shape people’s behavior much at the level it will be set at.
Second: Autonomous cars, certainly there are fewer autonomous cars than toll roads. The mileage of successful tests for autonomous cars is growing at an exponential rate, and is looking primed for take-off. This is more speculative than some others. However this feels like a trend which will shape transport.
Third: Changes in working hours are due to increased productivity, primarily the increasing embeddedness of information technologies in general practice of everything that we do, so I think this is a social implication of a technology.
I read this headline to my students, who started laughing.
Detroit, yes Detroit, Michigan is looking to widen a major highway, because presumably, it is the lack of highway access that is constraining economic growth. Obviously these are different agencies doing the planning, but in an era of peak travel nationally, what must the travel demand statistics look like in a declining city like Detroit.