Category Archives: facilities


David Levinson and I authored, “The Shapes of Streets to Come – How New Transport Technology will Reshape Urban Space” which appeared in European Financial Review (registration required) (reprinted below). [PDF version here: TEFR AugSep 2016 – The Shapes of Streets to Come – How New Transport Technology will Reshape Urban Space]


By David M. Levinson and Kevin J. Krizek

Autonomous vehicles are coming. At their best, AVs are stimulating an impulse to drive genuine innovation. At its worst, they are a hubris that causes us to overthink the solutions to transport problems in cities.

Big changes are coming for how people will get around in cities across the globe. The most important change will hinge on the introduction of autonomous vehicles (AVs). Simultaneously, cities will witness the conversion of the vehicle fleet to being primarily electric-powered (from a grid rapidly converting to renewable energy and off-the-grid solar charging) and new ownership models like shared mobility become more common.

The overall pace of deployment of AVs and their effects will vary by the size of the city, the cost of labour, and the desire for politicians and their constituents to innovate. How all of these factors play out on the multiple stages and multiple scales (e.g. the neighbourhood, metropolitan, and national levels) will prove exciting to watch. The best part is that you not only get to observe how things will play out; you get to participate as well. We preview many of the prevailing tensions of this emerging landscape below.

Autonomous Vehicles

After decades of technological slumber in the automobile industry, self-driving cars are here. Rolling on the roads today in semi-urban environments are cars that can recognise speed limits and adjust their speed instantly. They can maintain a safe following distance from other cars, and brake when needed. They can even recognise the difference between cars, buses, and cyclists. The technology is at the cusp of being widely deployed, something that will take place over the next two decades. Significant other hurdles, however, lie ahead. These impediments include how cultures might adapt (e.g. how quickly will people surrender control, and their comfort with technology), legal regimes might change (e.g. standards, reconciling responsibility in crashes, the role of licensing), and street designs will be altered (e.g. the extent to which AVs will be apportioned separated lanes on different types of roads, and how soon human-controlled vehicles will be prohibited in places). We focus on the last hurdle here.

One of the strongest but often unrealised arguments for the advent of AVs relates to street capacity. Where today a freeway travel lane is typically 3.6 meters wide, with AVs, a standard lane might only have to be 2 meters (just wider than the width of a full- size car or SUV). This alone nearly doubles capacity. Farther into the future, lanes might be dynamically resized rather than permanently fixed in paint. Being automated, these cars can trail one another more closely as well. Instead of following at two seconds or one-and-a-half seconds, they might follow at one second or less, increasing throughput.

Today the average vehicle carries only one or two people, yet the average vehicle has seats for four or six or eight passengers. The fleet is oversized, especially in the US. Americans have a propensity to buy large cars for the few times when they may need it. The extra seats, however, sit unused most of the time. Automation, combined with mobility-as-a-service presents opportunities for new vehicle forms.

New Types and Forms of Cars

Smaller one and two-person vehicles can be the new standard, and larger cars the exception, only summoned on demand when needed. In lower density areas, travel distances remain large, but the use of AVs will allow suburbs and small towns to wring out more road capacity, provide good arguments against road expansion, and claw-back space that has been given over to parking.

A city can start to realise large benefits because it can get more capacity out of that smaller vehicle, more energy efficiency, a greater range for the battery, and so on. One of the more noticeable elements will be a transformation of the shape of the car. Vehicles will begin to sport new designs whose markets will be defined by required use. Consider an enclosed motorcycle that’s electric, quiet, safe, stabilised, and automated. It is safe because, not only is the vehicle designed well, with a roll bar and all that, and because it is driven by a computer with nearly instant reaction times, but because all the other vehicles are also automated. Small cars require less space and it is easy to see how future cars will starkly contrast with their ancestors. Meanwhile, sensors and computers replace the human-facing control functions; electrification is changing the entire motor system, so future cars will be simpler to manufacture and maintain than the internal combustion engine.

Innovations in Related Modes

The complexity of how and when – not if – to accommodate AVs will be further complicated because other modes of transport are re-inventing themselves as well. Different types of mobility-as-a-service are coming on line. These include new forms of taxis and transit services that are both smaller and bigger than a standard bus. Taxis will be more extensively used because the vehicles are smaller and driverless, and so cheaper. In urban areas, there will be more frequent transit services in selected corridors, which will be less expensive to provide as labour is automated away. Elsewhere, today’s infrequent bus and commuter rail services will be replaced by mobility-as-a-service type of options; instead of having a bus that comes once an hour, people will be using taxis – often single passenger taxis, maybe shared ride taxis. While the exact market configuration (who owns, who rents, who shares a ride, who rides alone) will be sorted out over time, it is clearer to see how, like today in Manhattan, people who live in dense cities won’t be owning cars, but instead will subscribe to a service, buy the services on demand, or find it provided by the public as a “free” utility, like the elevator in an office building

Role of Walking and Bicycling

Amidst this uncertainty, bicycling and walking will thrive for shorter and medium distance trips. These might be trips where people yearn for physical activity or just want to be outside. Their use will continue to be constrained by weather and hills, though e-bikes, with electrical pedal assistance, will mitigate some of that. This is one of the reasons we will likely see an increase in the attention devoted to physically powered movement for next few years. It is green and energy efficient. It makes many people feel better. Most importantly, bicycling and walking are modes that are relatively known and proven in selected markets.

All of this is to say that traditional modes, bicycling and walking will continue to exist and begin to thrive even in the US. This owes to increased population densities in central cities (and trip distances therefore decreasing), increased safety because AVs are less likely to kill them than human driven vehicles are, and a growing inclination to more fully connect with others and their environment.

Infrastructure Needs and Who Gets What Space

How will street space be appropriated in a manner that will allow multiple modes to harmoniously co-exist? Answers to this question will play out differently between and within cities. Fundamental geometric limits ultimately dictate the usefulness of these improvements. Where the intensity of development is higher, several modes will compete for the same space. Different modes can safely mix in the same shared space at slow speeds, as is now found in historic sections of many European cities. Further away from these cores in lower density areas, where space allows, the infrastructure provision for modes will be more segregated.

Typically, local municipalities operate the local streets and state or regional agencies maintain the connecting the backbone. On the backbone, we envision special (managed) lanes for automated cars for a period of time, just as today we have express, HOV, or high occupancy/toll lanes. It may even be the same lanes will benefit all users, as separated lanes will allow reaping the benefits of closer following distances than possible with mixed (human plus automated) traffic. As all vehicles become automated, all lanes will be managed.

Shapes of Streets and Shapes of Cities

The ability for cities to dynamically reconfigure lanes and repurpose streets will be the central challenge. The speed and manner in which cities and regions respond to the onset of these big changes will vary. Some places will move quicker than others. Politics and openness to innovation will be important. But ideas are light baggage, and successful policies will be quickly copied and emulated.

Shapes and patterns of development of communities determine how most people get around. The size and nature of buildings and roads are important. The prevailing perspective is that cities have evolved under different technological and political regimes; they therefore embody the DNA of their continents. Granting exceptions, North American cities have a DNA that is distinct from their Asian, European, or Latin American counterparts. Cities in Europe are smaller in size, they were mostly formulated in an era prior to automobile, and their networks for movement are more multi-modal. It’s sometimes easier to get things done without a car, automated or not. Hundreds of European cities already have an extensive track record severely limiting automobile traffic in historic districts. The Italians call it the ZTL (Zona a Traffico Limitato). We expect European cities will be keener to take back even more street space from the new AV, and use it for landscaping, linear parks, cycle tracks, and high-frequency transit services. Places in other parts of the world will follow suit.

AVs and the Future of Cities

At their best, AVs are stimulating an impulse to drive genuine innovation that will make lives richer and more connected, faster and safer, and more productive. At its worst, they are a hubris that causes us to overthink and over-engineer the solutions to transport problems in cities. Either way, AVs are coming. It is just a matter of when and how.

Political and legal systems in cities will be forced to play catch up with technological systems. The cities that do will win the 21st century. The others are building unnecessary capacity justified by extrapolating the exhausted trends of the past. The aim of transport should be ensuring people and goods can reach their destination safely and efficiently. This requires focusing on what will improve access tomorrow, not what might have increased access yesterday.

Featured image courtesy of the author Kevin J. Krizek

About the Authors

David Levinson and Kevin J. Krizek are the authors of The End of Traffic and the Future of Transport, available on Amazon Kindle and Apple iBooks.


David M. Levinson is Professor in the Department of Civil, Environmental, and Geo-Engineering at the University of Minnesota and will soon be joining the University of Sydney. He holds the RP Braun/CTS Chair in Transportation.


Kevin J. Krizek is Professor and Director of the Environmental Design Program at the University of Colorado-Boulder. He also serves as the visiting professor of “Cycling in Changing Urban Regions” at Radboud University in the Netherlands. Krizek was a 2013 fellow of the Leopold Leadership Program and was awarded a 2014 US-Italy Fulbright Scholarship.

Cycling safety feedback loop |

My post, Cycling Safety Feedback Loop is up at…

“Assuming cyclists have “safety in numbers,” the real question I posed in my last post is how can St. Paul or Minneapolis (or Anyplace, Minnesota) get more people on bikes?

The trademarking of “Copenhagen” cycling nomenclature

Utilitarian cycling is exceptional in Copenhagen for a variety of reasons. The global cycling community has rightfully adopted their many of their innovations. But I am mostly intrigued in how the cycling community has accepted the Copenhagen “trademarking” in common nomenclature. We have:

Copenhagen bike lanes. [Has this term slight fallen out of favor, being replaced with "cycle tracks?"]

The Copenhagen left.

The Copenhagen Greenwave. 

Are each of these indeed invented in Copenhagen? Is there a “machine” behind their naming? At what point in having other communities adopt such practices should they no longer have the “Copenhagen” label?


Diminishing returns of off-street bicycle facilities |

At, I have the following post: Diminishing returns of off-street bicycle facilities.

“Some attention to my previous post seemed to stem from the incredulity of implying anything negative about the Midtown Greenway—one of America’s most beloved darlings of a bike path […]“

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.

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.

Pedestrians and cyclists can get hurt even on NYC sidewalks, but the heavier ones less so

The NY Times reports on an article re: pedestrian and cyclist safety from the Journal of Trauma and Acute Care Surgery.

-Gathering data from 1,400 people who have been injured is impressive.

-That pedestrians are most vulnerable in crosswalks is not surprising; it is where the pedestrians are–the whole “exposure” aspect.

-But now, we finally have a partial silver lining to the obesity epidemic in the US: excessive weight may prove a boon for pedestrians in a collision. Victims with an above-normal body mass index were found to have less severe injuries than their counterparts. “It is not implausible that a greater proportion of torso and extremity fat may protect against injury”