If only you were representative of the mainstream of the traffic engineering profession. Sadly, traffic engineers who are skilled, dedicated and knowledgeable about livable thoroughfares and the making of walkable communities are a tiny minority within the profession as a whole. I am glad to hear you do not “go to work trying to reduce access, widen roads, and limit connectivity,” but that is in fact the standard operating procedure for most new construction in the United States. There are thousands of practitioners who can confirm that unfortunate truth from personal experience. If it was not the case, there would be no need for initiatives like the ITE’s Context Sensitive Solutions for Urban Thoroughfares manual.

Having evaluated over 1,000 plans for new walkable developments, I have a solid basis for observing that the biggest, most common flaw is lack of external connectivity. You say that planners, politicians and commissioners are responsible, but those folks will usually say they are following the directives handed down by traffic engineers. And so the buck is passed along in an endless circle of denied responsibility. At least in the planning realm, the major professional organization (APA) has adopted an official policy that gives high priority to street connections in transportation systems. In the realm of traffic engineering, the leading organizations (AASHTO, ITE, etc.) have adopted no comparable policy position.

I agree with your observations about land uses and connectivity. As I wrote in Part 4: Neighborhood Walking: “A consistent theme running through the studies is that connectivity works synergistically with other urban design elements to support walkability. When tested by itself, connectivity may show little relationship with walking. When tested in concert with other design elements like proximity to mixed use, connectivity has a significant impact on walking.” See the rest of Part 4 for more detail on this topic.

You ask whether unwalkable suburbs are a function of roadway design or land planning. However, roadway design and land use planning need not be in conflict nor mutually exclusive. That dichotomy may be common in conventional planning, coding and regulatory regimes, but is unnecessary and unneeded. Roadways and land uses can be coordinated through comprehensive urban design. For instance, the rural-to-urban transect, a concept that dates back to Patrick Geddes, can be adapted as a zoning code that address a full spectrum of walkable environments. Such codes can harmonize thoroughfare configuration, land uses, building form, setbacks, frontages, and other elements of urban design. A number of communities nationwide are adopting transect-based codes; the largest is Miami.

Finally, a word about insults. I have endeavored in this essay to place responsibility on the standards and practices of the traffic engineering profession, not on individuals. I suppose the degree to which one feels insulted depends on the degree to which one identifies with those standards and practices. But they have delivered inferior safety performance, as well as inhospitable thoroughfares that function poorly for pedestrians, cyclists and transit. They contribute to a low degree of livability in built environments. Based on the record and the evidence, those standards and practices deserve all the criticism put forth in this essay.

Being a traffic engineer, I feel I’m being placed in a generalized category of nerds who just follow standards set before them with no understanding of context and no real ability to think for myself. That’s insulting. I got the same feeling as I read through The Boulevard Book. There may be some out there that fit that mold, but let’s be clear that the reference to “traffic engineers” is certainly not all-inclusive.

I work in Chicago and deal with many projects in vibrant, urban, and downtown neighborhoods. I take the L to work everyday. My family has just one car… we walk a lot. I’m all for livable streets that are walkable and accommodate multiple users from autos to bicycles to pedestrians to transit. I don’t go to work trying to reduce access, widen roads, and limit connectivity.

I’ve worked on many studies in Chicago in neighborhoods with a lot of pedestrian activity, transit use, and a traditional street grid (some with 300-foot blocks), but most of those cases, traffic sucks. That’s just reality… many people will continue to insist on driving. We just need to manage it the best we can and incorporate design aspects that make it easy to walk, accommodate transit, and improve the overall character of the area.

I’m all for reducing our dependence on private auto and using other modes to get around. But in most suburban and rural areas, walking is typically not a viable option for most people. Whether that is a function of roadway design or land planning may be debatable. Is it the classic chicken-and-egg situation.

I think providing livable streets that are walkable, safe, and inviting for all users has as much to do with land use planning, if not more, than traffic engineering. If people have nothing to walk to, I don’t care how short your blocks are. Land uses need to be more integrated with each other. I’ve never been asked to design the roadway system for a new development as a starting point. Planners are typically responsible for that. In most cases, it seems driven by getting the right number of units or square footage in the plan, getting the stormwater and utilities to work, and then trying to make the transportation work for that plan.

Unfortunately, I think the way most communities, outside of existing urban areas, are formed these days by the decisions of politicians and commission members who don’t have a clue about good land use and transportation planning. They lack vision and the willingness to try something because it may be unconventional or unpopular among constituents (who more often than not are complaining about traffic).

Sorry for the rant, but I think your blanket take on traffic engineers is a gross mischaracterization.

I am not aware of any corridor access management plans that have formed the basis for livable streets, but would be interested to learn about any existing examples.

Master street plans can be a great tool, and of course many popular and successful American neighborhoods are based on master street plans. On the other hand, in the documentary Contested Streets, planners in Copenhagen make an intriguing point. They say Copenhagen’s 40-year redevelopment as a pedestrian and bicycle oriented city could never have proceeded under a master plan. There would have been too much opposition, too much resistance. In Copenhagen, the incremental strategy has been much more viable and has produced excellent results.

The bigger problem with regard to livability and modal options is inadequate local street network development. Master street plans are starting to catch on (again) and local access management policies are helping accomplish a more diverse and connected street network in urban areas. Unfortunately, most corridor development is administered incrementally, rather than in the context of a detailed development/street plan. Corridor access management plans are a great tool in that regard and can form the basis for development of livable, walkable places with highly connected street networks and modal options.

I fully agree that the level of carnage from traffic crashes in the U.S. is horrific. That was in large part the motivation for writing this essay. As I pointed out, over the past 40 years the U.S. per-capita traffic fatality rate went from one of the best in the developed world to one of the worst in the developed world. The U.S. improved over that time period, but the European nations improved much more. The U.S. traffic engineering profession should learn from the principles underlying Europe’s superior performance, including livable streets and walkable, highly connected neighborhoods.

There is no doubt that the statistics Demosthenes cites are accurate. However, as I argue in the essay, the devil is in the details. Access related crashes are 65% of the total in urban areas, but are we talking about exurban, suburban or livable contexts? Demosthenes cannot answer that question, because the traffic engineering field as a whole cannot answer that question. Context is simply not on their safety research agenda, in spite of the fact that it plays a major role in traffic crashes.

Demosthenes wrote:

The article ignores the community’s needs and demands for mobility. It never mentions the level of carnage on public roads.

This pair of sentences crystallizes the cognitive dissonance inherent in much of traffic engineering thinking. The community’s needs and demands for mobility — realized in the form of high speed, passive-safety thoroughfares — are directly responsible for the level of carnage on public roads.

One solution — the conventional solution — is to build ever larger, ever faster arterials carrying traffic ever longer distances, and then to restrict connectivity in an effort to compensate for the dangerous conditions that result. I advocate a more direct and efficient solution: Walkable neighborhoods. Reducing the number of miles people have to drive. Making streets livable, safe and inviting for pedestrians. Providing bike, transit and other travel alternatives.

When Demosthenes mentions prosperity, I assume he is referring to congestion, hours of delay in traffic and the associated costs. As I described in Vehicle Miles and Traffic, greater connectivity can reduce congestion. Walkable neighborhoods with livable streets reduce per capita VMT. Alternative travel modes like biking and transit are much more viable with livable and well-connected street layouts.

Access management does have certain benefits. I hope no one assumes that I am opposed to all aspects of access management. As I mention in the essay, limiting the number of driveways on arterials is beneficial. What I am specifically arguing against are intersection spacing standards that mandate long, unwalkable blocks for livable streets.

Finding balance is indeed a challenge. In my opinion, the balance has been wildly tilted in favor of automobiles for many years. In the spirit of better balance, I hope that Demosthenes and his like-minded colleagues will investigate in more detail the multiple benefits of livable streets, short blocks and highly connected street layouts.

The article ignores the community’s needs and demands for mobility. It never mentions the level of carnage on public roads. Over 830 fatalities weekly including 45 children, and 7,400 injuries daily. Access management achieves crash reductions of 30 to 60%. Access related crashes are over 65% of the total in urban areas. Every day, members, friends and relatives in our communities are lost forever, or are hospitalized. The most likely cause of accidental death in the USA is a traffic ‘accident’.

I am a supporter of good neighborhood design and livable streets. But the transportation system is much larger than that and a vital part of American prosperity. Finding the balance between the needs of neighborhood public ways and the collector and arterial regional distributors is a challenge to land use development, urban design and agency institutional policies and procedures.

Access management is not wrong as Aurbach seems to suggest. Access management is set of strategies, technical tools, that if used wisely and in context with the community, improves the quality of life by improving the quality of travel and the safety of all users of public ways.