The paths that people take (5 part series)

As part of an interesting FIVE part series focusing on different considerations in the paths that people take for travel (i.e., why is it not always the shortest?), the Transportationist discusses our bicycle route choice experiment.

Why reduced congestion is a weak argument for cycling

In 1991 the City of Münster (Germany) aimed to raise support for the city’s spending on bicycling infrastructure. The press office of the city made a poster comprised of three panels. Each panel’s background displayed Münster’s Prinzipalmarkt, the cobblestoned main street in town; what differed in each panel was what filled the Prinzipalmarkt. The first depicted what the street looked like if 72 people were transported by car; the second, by bus; the third by bike. The main point was that bicycling is an extremely efficient way to use limited transport space in cities.

Twenty years later, Indian-based organization, Earthian, posted the figure to Facebook. It quickly went viral[1]. The graphic has since been used prominently in presentations worldwide to advance the arguments that bicycling is a strategic means of transport; bicycling can help reduce traffic congestion. In theory, it makes sense. And, the “reduced congestion” argument is one of the more prevalent ones in the advocate’s arsenal. It carries water for places with exceptionally high cycling use or for specific corridors. The argument, however, is fatally flawed when applied to larger units of geography.

The source of the substitution

The implicit assumption in the reduced congestion argument is that there is a substitution effect between a cycling trip and a vehicle trip. If true, it is helpful to consider the source of the substitution and its magnitude. For example, using mode share figures based on the US, a starting point suggests bicycling would draw from other modes in proportion to their current mode shares[2]. Bicyclists would therefore draw roughly 85 percent of their market from driving trips (solo or with others), 10 percent from walking trips, and the remaining from transit or other[3]. If most converters would come from existing transit users, a reasonably safe assumption but a population whose travel comprises a meager two percent of travel (again, in the US), then these numbers are relatively small. Tapping into the mindset of converting auto users presents a greater challenge.

The magnitude of the substitution

Understanding the magnitude of the substitution effect is difficult mainly because it is based on a counterfactual condition (e.g., if Booth would not have killed Lincoln, then…). There are two ways to think about it. One can start with a fixed number of vehicle trips and assume a share of those trips that are replaced by bicycling. Alternatively, one can consider the number of bicycle trips and estimate the share of these trips that replace driving. The two analysis strategies are not comparable.

Our own work found a wide range using the later approach, ranging between 25 and 68 percent of bike trips claiming to substitute for car trips[4]. This suggests that half of the existing bike trips, were they not by bicycle, would be by car. Such rates of substitution, I presume, vary wildly across the globe. Then think about places where cycling comprises more than half of all trips: Groningen (the Netherlands), Münster (Germany) or Copenhagen (Denmark). It is hard to conceive of the character of these iconic bike-friendly cities if most trips were by car. Most bike trips substitute and the congestion savings is remarkable. But outside of these select settings, it is hard to know. In the rest of the world, if the logic is applied to a particular corridor, the congestion savings argument might have a noticeable impact.

Vehicular travel is not fixed

For most cities, there is a there is an inherent fatal flaw with the foundations of the above logic. These flaws become apparent when congestion is considered on a larger scale or for places that are growing (the birth rates in the above mentioned towns are not exactly skyrocketing). The foundation assumes a fixed demand for travel, and vehicular travel in particular. Prevailing trends of population growth and auto ownership suggest otherwise. Coupled with what is generally known about travel behavior, and driver behavior more specifically, these factors paint a meager picture for cycling’s ability to address congestion.

Traffic congestion is a problem is that is both old and complex. Rome struggled with it, resulting in Caesar simply issuing a ban on carts and chariots back in the day. Things aren’t that easy in most cities and more recent thinking has focused on its source and solutions. A good portion of that thinking is framed around issues of capacity: building more roads or widening existing roads and what is referred to as the effects of induced demand[5]. Any form of relief provided for drivers, the story goes, will quickly be gobbled up[6]. Drivers will defect to the corridor where the relief is offered. Other drivers, previously sleeping in and starting their commute at 9:30 will join the 8:00 am rage. Still others who were previously carpooling or using transit, learning that their route is as bad as it used to be, will switch to driving. Add traffic from the inevitable new development down the street and any immediate gains become a wash.

A key outcome from most of this thinking has been coined the “Iron Law of Congestion,” suggesting that once congestion has reared its ugly head in a city, there is little the city can do get rid of it. Congestion is largely an inescapable condition in all large and growing metropolitan areas across the world.

The same logic applies to gains from getting more people on bikes; it might provide temporary respite which would be gobbled. Suppose a community cycling initiative can leverage the previously explained phenomena to the fullest. Transit users and car users alike convert to bike travel for most trips. Getting more people on bikes might mean less people driving cars; it might mean temporary relief in the previously congested corridor. But using the Iron Law and considered across the region, the effects on congestion would be futile.

Congestion is less about capacity

But that’s not all. Driver behavior is also a culprit to congestion. Tom Vanderbilt’s book, Traffic, climbed its way to become a top ten best seller on the New York Times list in August 2008. It is the only book focused on transport that has claimed such a coveted spot. One of Vanderbilt’s principle claims is that traffic congestion has more to do with driver behavior than capacity issues. Drivers switch lanes, rubberneck, merge too early or overcompensate when braking—all relatively small flaws in driving behavior—but in the aggregate, they have a major impact on congestion.

Such driver errors and their consequences on congestion will diminish over time; automated vehicles will likely clean up such mishaps. However, this stream of thought suggests congestion has less to do with overall capacity in general. Even further evidence of the importance of the operations of a system in terms of congestion comes from New York City’ recent experience. Over the past years, the city has been aggressively reallocating select street space for cyclists and pedestrians, thereby decreasing overall vehicular capacity. Analyzing taxi cab logs, however, the Bloomberg administration contends that travel speeds have remained steady despite such decreased real estate—an outcome that is largely attributed to improvements to the city’s traffic signal system[7].

Larger fish

Cycling’s limits to reduce congestion is perhaps best understood when the argument is taken to an extreme. Scaling up to large and quickly growing cities, the latent demand ready to consume any relief to existing congestion is overpowering. Projections from the United Nations paint a picture of adding more than one million people to the earth every five days for the next dozen years[8]. Admittedly, the majority of this growth will be absorbed in cities of developing countries and its impact being unequally distributed and perhaps even barely felt in Europe. But with rising incomes generally across the globe, the more than 60 million cars that are produced each year (more than 100 new cars every minute) will likely find willing drivers[9]. The primary drivers to congestion (pun intended) are more powerful than anything that bicycling can realistically impact over the next decade or two, globally speaking.

There might be good reasons to spur bicycling and build more facilities to do it. The congestion relief might be felt locally. Aiming to reduce congestion on a regional level, however, is one of the least reliable rationales for doing so. Cyclists are better off making hay from other, more reliable arguments.


[1] http://news.medill.northwestern.edu/chicago/news.aspx?id=190533

[2] Transport econometricians refer to this as the principle of Independence from Irrelevant Alternatives (IIA)

[3] Summary of Travel Trends: 2009 National Household Travel Survey, http://nhts.ornl.gov/2009/pub/stt.pdf

[4] Piatkowski, Dan, Kevin J. Krizek, and Susan Handy (2013). Accounting for the Short Term Substitution Effects of Walking and Cycling in Sustainable Transportation. Working paper available from the Active Communities / Transport (ACT) Research Group.

[5] Most of the original research is attributed to David Lewis [(1977), Estimating the influence of public policy on road traffic levels in greater London. J. Transport Econ. Policy, 11, pp. 155–168] and Martin Mogridge [(1990),Travel in towns: jam yesterday, jam today and jam tomorrow? Macmillan Press, London].

[6] Anthony Downs is largely credited with popularizing some of predominant thinking, starting with his 1992 book, Stuck in Traffic: Coping with Peak-Hour Traffic Congestion (1992), The Brookings Institution: Washington, DC. The concept is better explained in his updated work a decade later, Still Stuck in Traffic (2004), The Brookings Institution: Washington D.C.

[7] See, for example, http://www.nytimes.com/2013/09/05/nyregion/in-bloombergs-city-of-bike-lanes-data-show-cabs-gain-a-little-speed.html or other reports such as the “Green Light for Midtown Evaluation” (January 2010), from: http://www.nyc.gov/html/dot/downloads/pdf/broadway_report_final2010_web.pdf

[8] Population Division, United Nations, Department of Economic and Social Affairs. World Population Prospects: The 2012 Revision.

[9] Figures provided by the International Organization of Motor Vehicle Manufacturers, see: http://www.oica.net/wp-content/uploads/2013/09/total-production-2013.pdf


Kolkata, India Bans Bicycles on Key Corridors

Here is the latest example of a city from a developing country that is banning bikes along key corridors. Two questions come to mind:

(1) The article says the ban applies to “most thoroughfares.” What percentage of usually available cycling roadway space is “most”

(2) The “authorities” cite “security concerns as bicycles are often used to plant bombs.” This is a new one for me.

Documentary of bikes vs cars from Swedish film directors

Based on the trailer alone, I am not rushing out to see the new documentary Bikes vs. Cars. It seems to me we have already been through most of these arguments, especially from advocates. I guess it might be new for a Swedish director. The “international flair” might be new. But otherwise, I hope documentaries like this dig a bit deeper. Maybe it does.

The eternal nature of transportation corridors, but reconfiguring them

This past weekend I visited the “the Eternal City,” Roma, Italy. The Romans thought that no matter what happened to the world, no matter how many other empires might rise and fall, their city would be everlasting.  Most cities have ups and downs; their transportation corridors, usually, are another story; most have eternal lives. Once a transportation corridor is cemented (pun partially intended), it has a staying power rivaled by few inventions or fabrications in the world. Some of original paths worn by the Etruscans outside my apartment in Bologna today continue to serve as main conduits of economic activity for the region. Gravity has determined the outcome of most original Roman structures, but their roads are also still widespread throughout parts of Europe, Africa and Asia. Even the canals in northern Europe, built by the Roman empire for irrigation, later helped the British pioneer the industrial revolution; these canals y are still carrying barges, albeit leisure ones. The transportation function along any corridors rarely exists in its original form. Technologies change. Types of economic activities change. Fashions change. This largely explains why you don’t see many donkeys filling the streets in Israel anymore. Outside of the nostalgic horse and carriage for tourists and weddings in Paris, there are not many of them on the streets either. The streetcars employed in hundreds of cities across the US have been torn up for car only use.

The transportation future of cities will continue to be surface-based, with cars and existing roads playing prominent roles. But over time, the nature and character of select corridors change to better serve the needs and demands for other modes. More overall space will be made available for bikes—a contentious topic but one whose writing is largely on the wall. A sticking point is where to find the space for this change, a proposition that will require altering the nature of many transportation corridors in cities.

With urban areas built up, cities largely have four options before them to find more space. They can: (a) extend in another dimension, aerially or subterranean, (b) find new right-of-way space, (c) widen existing right-of-way space.  These first three options are either technologically difficult, involve displacing people (rarely a good idea) or are prohibitively expensive.

A fourth option requires cities to reconfigure existing space by altering the use patterns along it. Changing the nature of the transportation services along a corridor. In most cases, this option involves scaling back car use in one way or another. This is analogous to taking candy away from a child (taking space away from cars). And, its trouble points are primarily political (not financial or logistical as identified in the prior solutions).

Many corridors in urban areas already have initiatives that are rethinking the role that the car has played in the past half-century. These initiatives range from charging for or banning car use during certain times, reducing capacity by removing a travel lane, reducing capacity by reducing speed (via narrower travel lanes), removing on-street parking or all together, turning a street over to other modes. These are all steps in the same direction. Cycling’s ability to realize these gains rests in its ability to better leverage these types of initiatives by downsizing existing facilities and gently expanding alternative networks. But not all roads. Just select ones.

Where is the low hanging fruit and what criteria can help cities reinvent corridors for cycling?

  1. Communities first need to identify stretches of road that have “proven” themselves from a cycling perspective. These places might connect key origin-destination pairs. They might be currently serving cyclists who are experiencing hardship conditions. Then there are two synergistic interventions.
  2. The second step is scaling back car use. Addressing the fact that high vehicular speeds are the largest culprit to unfriendly bike environments is key. Harnessing cars to speeds below 40 km/h is necessary. If a community accompany such speed limits with reductions in the widths of vehicular travel lanes–or even the removal of some of them—all the better. (Pushing such a proposal through the political process likely involves a gentle nod to address how alternative corridors might be able to better absorb some mild enhancements to vehicular capacity via intersection design, signal timing, or on-street parking modifications.)
  3. Building up cycling facilities. Designated cycling corridors, at a minimum, deserve on-street delineation of cycling routes. This might start with a marked lane, a buffered lane (with paint), a raised path, or even physical barriers from adjacent traffic. Furthermore, intersection treatments go a long way.

Transportation corridors have amazing staying power. Cities can and should work with their existing bones to further cycling; they don’t necessarily need to search endlessly for new corridors. But there is nothing to suggest that the existing roads cannot be downsized for car use or more generally, have their purpose altered along select routes.

The perfect is the enemy of the good; making lemonade is sufficient

Some bike paths serve as semi-icons for their city. The Creek Path in Boulder, Colorado (US) ranks up there with the Seattle’s Burke Gilman Trail and the Chain of Lakes network in Minneapolis (both US). But the origin of the path’s construction had some rough beginnings.

A bit of history: The area around the path was originally called for in Boulder’s Creek Corridor plan (1984), which stipulated the use of the creek corridor as a linear, topographically sensitive park. This park would incorporate riparian zones and wetland sensitive elements[1]. The creek comprised one of the primary watersheds for the city and a few years later, the city purchased adjoining land to the creek for a wetland and greenway program. This led to further integration of habitat restoration and water quality augmentation elements into the use of once forlorn features of Boulder’s ecological fabric. But over time, community-wide momentum was building for how the area could also enhance flood mitigation efforts together with more “mainstream modes” of transportation such as walking and cycling (in addition to kayaking)[2].

Rather than scour for the pennies that were available at the time to build bicycle facilities, the city tapped into federal grants for flood control and environmental remediation; these coffers were three to four times larger. The city creatively parlayed bike trails into this process. The flood mitigation efforts were considered to have largely passed the extreme test that the city experienced owing to biblical floods in September of 2013.

But the specific planning of the bike portion of the Boulder Creek Path was somewhat of a separate issue. And, Gary Lacy, a recreation planner for the city at the time, approached it with vengeance. He focused on ensuring it got built—not planned for—but built. Lacy considered formal permits a nuisance; conscientious and collaborative plan-making was too time consuming. He relied on a “Robert Moses-esque” philosophy and sometimes took a page out of Chicago Mayor Daley’s planning playbook[3]. Rather than abide by city protocol, he went solo and blazed sections of the trail by moonlight. He took to the backhoe to move obstinate boulders along the way. Where the earth would not move, he built the path around it.

Lacy’s semi-barbarian approach to make the path is etched into local folklore. And the path itself would have made the hair stand up on the neck of the authors who penned the 4th edition Guide for the Development of Bicycle Facilities by the American Association for State and Highway Transportation Officials (AASHTO)[4],[5]. Sight lines are jeopardized, travel lanes were inconsistently wide, and some right-angled turns (frowned on in bike path planning) continue to be sprinkled throughout. Friends in town claim the trail is hazardous and a downright safety hazard. But the path got built—the city has since smoothed out some of the path’s rough edges—and it now serves as a beacon for the city and a seminal spine for the rest of the its cycling network.

The development of Boulder’s Creek Path represents a planning story where the perfect was not the enemy of the good. Things got done, despite not being perfect. There were some issues along the way—some of them safety oriented, others process oriented. But its evolution begs the question in the world of bicycle planning, when is a facility “good enough.”

Similarly, the “so-called” bicycle facility outside my home in Bologna (Italy) is a meandering stripe that bobs and weaves, literally at right angles between newsstands and trees. It sometimes pinches the rider down to mere inches. I presume it was laid by an Italian public works employee after too much grappa. But do these sketchy attributes warrant it as a non-useful facility? Is providing substandard bicycle facilities worse than none at all?

The dilemma reminds me of a scene in Cher’s 1987 Academy award winning film, Moonstruck (the movie, likewise shares Italian origins). The father, Cosmo Castorini, is a plumber who is explaining to a client in his deep Italian accent his philosophy of preferred plumbing materials.

“There are three kinds of pipe. There’s what you have [aluminum], which is garbage – and you can see where that’s gotten you. There’s bronze, which is pretty good, unless something goes wrong. And something always goes wrong. Then, there’s copper, which is the only pipe I use. It costs money. It costs money because it saves money.

Did Cosmo have it right? Are there problems in the bike planning world that stem from constructing the equivalent of ‘aluminum’ or ‘bronze’ facilities?

The biggest risk of substandard facilities are the unmet expectations that they create. Cyclists, seeing signs, markings or other might are comforted into letting down their safety guard, for example. There is subsequent confusion about the role, rights, and responsibilities in the transportation hierarchy. Cyclists are all too familiar with the bike lane painted within mere inches of the impending car door opening. Or the bike facility that, in a pinch, mixes you with pedestrians and then switches the side on which bikes are supposed to ride. Then there is the blissful cycling corridor that abruptly dumps you into four lanes of auto traffic. In my own research, I found that users particularly struggle with these later situations when facilities end at bigger intersections, locations with on-street parking, and locations with relatively narrow travel lanes[6].

With most transportation networks being surface oriented, mainly along streets and primarily occupied by cars, it is useful to have prescriptions, guidelines, and even sometimes standards to guard against these situations. In an ideal world, a planner would take stock of the context, consult the guidelines, prepare the design, and execute. If only it were that easy. History gets in the way. Cultural peculiarities get way. Nature gets in the way.

There are many cities—almost all of them in industrialized countries—who are moving toward this consistent model. If you ask Dutch cycle planners, they immediately pull off the shelf their tattered Design Manual for Bicycle Traffic[7]. They leaf to dog-eared section 4.4.2 where they point to a figure with two axes—how many cars are along a particular route (e.g., traffic volume) and the speed of those cars. Five different types of suggested facilities are depicted based on these two factors alone. Adhering to some core principles put forth by the prototype model is gaining steam in the US[8] and cycling treatments are approached with increasing method and consistency.

At the other end of the spectrum lie cases where bicycling treatments are less than satisfactorily completed. That might be an overstatement. They are downright dangerous. These might consist of the cavalier bike path that was laid through a stretch of road—lacking attention to its connecting points—to enable a politician could deliver on a promise to a constituency. It might be the case where road engineers are blindly following a city’s guidelines; they might measure three feet from a street curb’s edge, lay a stripe, and call it a day regardless of the context. It might be the proverbial case where a bike facility passes over a storm sewer with drainage slots that miraculously measure the same width as a bicycle tire. No self-respecting transportation professional would endorse these outcomes. They present unexpected conditions, safety hazards, and problematic signals to both cyclists and car drivers.

In the broad spectrum of bicycle facility planning contexts, there are environments that are shy of falling into the above category. But, they don’t lend themselves to rigid standards (or expectations) offered in guidebooks. Try finding room for a bike path in the historic center of any city that was inhabited by the Romans. The typical right-of-way might be three meters wide and shared between five or more different modes each traveling in two different directions. While most situations are not this stark, the bulk of planning contexts—especially in historic cities across the globe—are in situations where the bike planner is dolled a bunch lemons. Cosmo might have had it wrong. Realizing that not everywhere in a city can be built with ‘copper pipe’ cycling conditions, bike planners must make due and prescribe treatments that are far from perfect. They must make lemonade, even thought it carries some risks.

Otherwise, what are their options? They could sharpen their pencils designing the perfect intersection which might come to fruition once the political will arrives. Alternatively, they could do nothing.

Making lemonade means that formal standards might be abandoned. Cyclists need to adjust their expectations. Car drivers need to acclimate. Life goes on. Bike facilities need to start somewhere. They need to be granted freedom to experiment without backlash. What might be considered a substandard intersection treatment today will eventually graduate to something more mature. For example, a painted stripe that winds through a parking lot, might be upgraded to a perimeter route next year, which would then eventually be dovetailed into a larger separated network. A green swath at an intersection now would convert to a bike box next year which would then be complemented with a prioritized cycling traffic signal in the following year. Doing “something” provides a much-needed nod to the cyclists. It is usually better than doing nothing at all and helps set in motion a process whereby facilities can mature. Cities are constantly evolving. This includes their transportation infrastructure. That is, over time, the lemonade gets sweeter and sweeter. Cycling treatments usually pale in comparison to the costs of auto or transit infrastructure. As long as lives are not gravely put at risk and accidents largely avoided—a big caveat, I admit—cycling treatments are inexpensive experiments. If they succeed, they are built on and further developed. If they clearly fail, they can be erased.


[1] A portion of the creek was reconfigured as a white water recreation park, thereby incorporating another level of complexity to the flood mitigation strategy. Gary Lacy, a recreation planner for Boulder and an avid kayaker, would reportedly boat to his downtown work location along the creek.

[2] Greenways Master Plan.   City of Boulder2001 update.  http://bouldercolorado.gov/files/Utilities/Greenways/MasterPlan.pdf. Accessed January, 2012

[3] Daley’s playbook: Meig’s field was a fully functioning private airport runway strip on Chicago’s pristine lakefrong. Citing security concerns in 2003, Mayor Daley ordered the bulldozers tear up the runway and they did so in the middle of the night to avoid obstruction and protesting efforts.

[4] American Association of State Highway and Transportation Officials (2012). Guide for the Development of Bicycle Facilities, 4th Edition. ISBN: 1-56051-527-2.

[5] This is a document that ASHTO was so proud about that they produced a video for its release, see: http://www.youtube.com/watch?v=WeE62AGXQZg

[6] Krizek, Kevin J. and Rio Roland (2005). What is at the End of the Road? Understanding Discontinuities of On-Street Bicycle Lanes in Urban Settings. Transportation Research, Part D. 10(1): p.55-68

[7] This report is the world’s most authoritative manual on bikeway design and is published by CROW—a Dutch acronym of the Information and Technology Platform for Transport, Infrastructure and Public space, a Dutch non-profit collaboration between government and businesses.

[8] As is evidenced by AASHTO publishing their 4th edition, American Association of State Highway and Transportation Officials (2012). Guide for the Development of Bicycle Facilities, 4th Edition. ISBN: 1-56051-527-2.

Where to Position Cycling in the Future Transportation Context for Cities

In order to properly position cycling amidst the larger transportation context in cities, we need to know more about what that future context of cities looks like. Just as every city or community has carved their unique path leading to its current situation, pushing that vision 50 years out is likely going to yield wildly disparate futures. Each path is shaped by a unique history, set of current conditions, culture, resources (which may or may not be available), and some unforeseen advents in technology. The future of Houston (United States) will be a stark contrast to Madrid (Spain), which will in turn not resemble Shanghai (China). And, the role of cycling in each will vary considerably.

There are several phenomena to consider in these discussions. A first has to do with the nature of growth in megacities (those with more than 10 million people) versus the growth that will be absorbed by other, smaller to medium sized cities. The second has to do with the predominant morphology of future growth. Will future development be comprised of high-rises or will it likely hover around a more manageable six stories? What will be the role of infill development? Third, what type of spatial interaction patterns will likely result? Are residents going to continue to geographically expand their circles for social activities and work or will there be a return to more localized interactions? No single projection seems to be winning out.

It is helpful to consider some prevailing global conditions to inform these discussions. There are more than a few trajectories to suggest that cities are destined for outward expansion; this suggests a decreased role for the benefits of immediate geography. The ubiquitous use of information and communication technology is the largest driver in this trajectory. As people rely increasingly rely on virtual social networks, they will rely less on their local and geographically based social networks, again, spurring, long-distance travel, if they chose to travel at all. In the transportation community, we have been talking for two decades about how telecommuting and delivery services will substitute for trips to get goods (e.g., clothing, food) and to go to work. While e-commerce comprises an approximate 5% of total retail sales (in the US), it is a phenomenon that has been increasing steadily[1]—and will inevitably to do so, thereby contributing to a trend people have less concern about living closer to services.

These forces combine with a seemingly insatiable appetite—at least for Americans—in variety seeking and comparison shopping. Prices and variety of goods will continue to play a strong role in purchasing decisions. This pushes large variety stores (e.g., big boxes) to get bigger and the trips to them less often but of greater consumption. The desire for variety is not limited to work or consuming goods. It extends to services such as schools and enrichment programs. Parents are increasingly maximizing their utility for the best overall school and fit; school districts increasingly offer this option via open enrollment. This trend diminishes the role of neighborhood schools and corresponding localized travel patterns. It, in turn, increases the burden on parents or school transportation districts to shuttle children across town.

While there are some convincing signs that the car—in its current form of a relatively lumbering machine, powered by a combustible engine, and driven by a human—might not be long for this world, the car will still be here to stay. The freedom, convenience, and privacy it provides is unparalleled with too many residents wedded to the services it provides. Furthermore, transportation networks, in most cities, are surface oriented, very mature, and predominantly structured around car travel. But cars will be increasingly smaller, propelled electrically, and driven autonomously. This will in turn increase mobility patterns for children, the elderly, and the disabled. It will ease the overall process of traveling by car, therefore leading to patterns of more and long distance travel which will facilitate exurbanization. These compelling forces paint a consistent picture of outward expansion that is less concerned about localized services. It generally weakens the central pull of cities—or neighborhoods—as activity centers.

But I believe there are other and more compelling factors to suggest that cities—and more specifically the geographic pull of neighborhoods—will ultimately win out in this tension. The ills of the traditional suburban model are now well exposed. There will always be individuals seeking both access to the big city but also pastoral living conditions; but these proportions will dwindle. On the other hand, I remain unconvinced that high-rise living is the ticket to the future. Skyscapers are less environmentally benign than is often considered[2]. This is has to do with aspects of their physical construction (e.g., being resource intensive and costly, lacking natural ventilation systems) and their effects on adjoining properties. Notwithstanding their density gains and other pleas[3], skyscrapers tend to be architecturally sterile and bereft of magic to feed human’s hunger for enchantment.

Future communities will necessarily be cognizant of their energy demands and their psychological effects; medium sized cities and towns are intrinsically better scaled for future energy realities but also humans’ intrinsic desire for belonging to a unique and localized sense of place. These places will be urban in the traditional sense of the word: compact, dense, mixed-use, and composed of neighborhood centers distributed throughout. A central transportation advantage lies in the scalability of this model. A neighborhood provides a sense of identity; several neighborhoods and a commercial district make a town; many towns comprise an average-sized city; many cities will form large metro regions. There is little new to this model. Its not a nostalgic call to return to traditional ways of occupying the landscape, just one that I think has staying power.

Traffic congestion will persist—and cyclists will still need to wrestle with it and its safety elements—but its overall burden to individuals will be less. It will be a different flavor of congestion given the increased use of smaller vehicles and sensors to better facilitate traffic management. Owing to automatic cars, people will multi-task in their cars even moreso than the average Italian does while driving and talking on their cell phone. Smartphones provide real-time information to endless services, easing the process by which different transportation services might be availed to the average traveler.

Then, if we believe in the diminishing role of gas to propel cars, this erodes the gas tax—a central source of funding for roads at all levels (at least in the United States). Local municipalities, realizing the demise of federal funding, will assume heightened responsibility for surface transportation, resulting in decisions that are better informed by capital, operating and maintenance costs and more equitably distributed across a variety of travel modes. Europe already does this well. The rest of the world will catch up in such thinking.

Putting the above factors to work as a visionary, I believe the land use-transportation future for most cities—big and small—is best captured in the following depiction. They will be oriented around central tenets of walkability, still allow car travel, and connected by rail lines. These urban places will exist on a much smaller scale than what is familiar to most people in big cities today, built on a much finer grain. Specifically, cycling will provide a much needed and valued connective tissue to bond both land uses and the other three predominant modes (walking, transit, car). Residents who live in urbanized areas—which would comprise more than 60% of the world’s population—would have a wide array of travel options available to them; many of these travel modes would rival one another in attractiveness or convenience. This means that common origins and destinations would be served by one or more of the following services: private auto, light rail, heavy rail, local bus, bus rapid transit, car-sharing, bike-sharing, walking, and of course, private cycling. Certainly not all services will be ubiquitous; however, most places would have two or more attractive travel options arranged in a seamless labyrinth of sorts where redundancy between modes is encouraged to the extent that resources allow.

These conditions culminate in environments not only accepting of bicycling but also help articulate a central role for it. I’m not going so far as to suggest that cycling will be the catalyst for a 21st Century urban renaissance[4], nor will it be the predominant form of transport (outside of select communities in Northern Europe). But, its status as a fringe mode will eventually be forgotten and cycling’s future will rest in its ability to “get along” and mesh with these other modes.


[1] See report and table at: http://www.census.gov/retail/mrts/www/data/pdf/ec_current.pdf

[2] http://bettercities.net/news-opinion/blogs/michael-mehaffy/14138/more-low-down-tall-buildings

[3] http://www.theatlantic.com/magazine/archive/2011/03/how-skyscrapers-can-save-the-city/308387/

[4] http://www.archdaily.com/409556/why-cycle-cities-are-the-future/

FHWA report/guidance on how to count bikes and peds

For the engineer in you–and for those seeking to learn more about the ins and outs of various counting technologies, the new version of the Traffic Monitoring Guide is now released. The new version includes, for the first time ever, a chapter on non-motorized traffic monitoring (Chapter 4) and a format for bicycle and pedestrian count data which would allow it to be included in FHWA’s traffic monitoring dataset.

A new form of cycling treatment?

Throughout my travels, I have seen many different style of treatments for cycling and pedestrian environments (e.g., ramps on stairs, raised paths to indicate cycle tracks, diverters to slow down bike traffic at busy intersections). While each country has their own flavor of treatments, most are pretty self-explanatory about what they are trying to accomplish.

 

However, in Bologna today, I saw one that mostly stumped me (see pic). Cycling is permitted on this stretch (as indicated by the paint on the pavement), but what they trying to accomplish/communicate with the track for the bike? My guess is that they want to slow down the bike speeds. But, apparently the gates alone are insufficient?

 

The future of cities, some reflections on reflections from Kunstler

James Kunstler’s first book, The Geography of Nowhere, was a strong force in exciting my interest in city planning. But the more I learned about the nature of cities and their dynamics, the more I saw through his journalistic view of the world. His ideas are persuasively presented, but typically barren of justifications and evidence. That is fine. He is a journalist and I am an academic.

This more recent essay from Kunstler (now two years old) is not all bad, however. He weaves together a variety of drivers on which to base a coherent and persuasive vision for the future of cities. I appreciate where he ends up. Though, there are more than a few outstanding questions:

-Are skyscrapers really not environmental?

-What about the semi-reliable predictions that the future of global population growth will reside in the equivalent of 10 new megacities of 10 million inhabitants each year for the next 20 years.

-Is there available real estate to develop at only the suggested 6 story level for such gargantuan growth? I have not run the numbers but I suggest not.

-A central premise of his arguments rests on the decline of cheap oil and water. Will this really be the case in 30 years? Have we not been hearing of such for the past 30 years? And, if it does become more scarce, who is to say that government subsidies–or lack of taxes–won’t diminish the impact.

-And, I certainly don’t get the impression that Harvard GSD is anti-new urbanism. Maybe I am missing something (again).

Professor, Environmental Design and Transport, University of Colorado