Making Streets for Walking: Dan Burden on Reforming Design Standards

urban_street.jpgA template for an urban street in "Designing Walkable Urban Thoroughfares." Source: Claire Vlach, Bottomley Design & Planning.

One of the foundational documents in our country’s history of car-centric street design is what’s known as the Green Book. These engineering guidelines, which have been published in various editions by the American Association
of State Highway and Transportation Officials (AASHTO) since the 1930s, are only "green" if you’re looking at the cover.

"We should take control of our streets. If 85 percent of our motorists are driving faster than we want them to, then we need to redesign the street."

Inside, the Green Book codifies an anti-urban design approach that transportation engineers have followed to disastrous effect in American cities and towns, creating wide streets where cars rule, speeding is the norm, and the greenest modes of travel have no place. While its recommendations are only advisory, the Green Book is often treated as gospel, implanting ideas like the "85th percentile" standard, which dictates that streets should be designed to "forgive" the 15th-fastest driver out of every hundred on the road. In the words of former Maryland transportation chief James Lighthizer, this is like building streets as though "everyone on the road is a drunk speeding along without a

Fortunately, these engineering standards are shifting. One important step is a new report co-authored by the Institute of Transportation Engineers (ITE) and the Congress for the New Urbanism (CNU). "Designing Walkable Urban Thoroughfares: A Context Sensitive Approach" aims to define a more humane engineering language for streets. The report is intended to supplement the Green Book by laying out a set of design standards that make sense in places where people can get around by foot or on a bicycle.

DanBurden.jpgDan Burden leading a walkability workshop in Lepeer, Michigan this February. Image: Michigan Municipal League

If, as U.S. DOT Secretary Ray LaHood recently pledged, walking and biking are going to have equal standing with motorized transport, more enlightened engineering guidelines will have to play a significant role. To better understand how the CNU/ITE report can influence state DOTs and the way they shape streets, we spoke to one of the experts who helped develop it, Dan Burden.

As the founder and executive director of Walkable Communities, Inc., Burden travels the country helping people plan and develop more sustainable neighborhoods. In 2001, Time Magazine named him one of the six most influential civic leaders of tomorrow. Burden spent 16 years as bicycle and pedestrian coordinator for the Florida Department of Transportation, so he was able to share with us his experience as both an advocate and an administrator.

Here’s the first part of our interview:

Noah Kazis
: Let’s start with that new ITE and CNU report that you participated in. What’s its significance?

Dan Burden
: A couple of big breakthroughs occurred with that publication. One where we struggled hard, but finally broke free, is setting a target speed for roads. Before, there was always the driving speed, which had to be higher than the posted speed to provide "forgiveness" to drivers. Of course, drivers totally figured that one out, and they’d drive faster than the posted speed. In these guidelines, they’re supposed to design the road for the speed that we want to elicit from the driver.

: Who is the target of this report? Who’s going to be implementing its recommendations?

: Any city or county engineer — anyone who is going to be professionally responsible for setting street standards for their own community — will be able to find that now there’s an official resource provided by the Federal Highway Administration that they can pull language from. It is truly an authoritative source. This collective body of professionals got together and agreed upon these new criteria.

: Is this a shift for ITE? Many of us think of transportation engineers as very conservative, very car-centric.

"The AASHTO Green Book is built for rural America and for suburban America. It was never designed for downtowns. It was never designed for the average neighborhood street."

DB: It is a shift for ITE. ITE, fortunately, is a little more progressive than the AASHTO, the American Association of State of Highway Transportation Officials, but this is a significant advance. It represents a blending of the transportation industry with the Congress for the New Urbanism. I don’t think ITE on their own would have been quite as bold. But with the leadership of the CNU, they really were able to bring in the best of the engineers.

: Besides bringing the posted speed and the design speed into alignment, what are the other innovations in this report?

: A lot of language was created to allow a more liberal interpretation of flexibility. We shouldn’t force any given category of street to fall under very tight constraints. We really need permission to build narrower roads, to use less asphalt, to green up the streets, to emphasize the need for walkability and bicycling, to bring down speeds on roads.

Turning_Radius.pngThe CNU/ITE report explains how adding bike lanes requires changing details like the turning radius of an intersection.

We shouldn’t just use some antiquated language that says we have to post the speeds according to what 85 percent of motorists are doing. Instead we should take control of our streets. If 85 percent of our motorists are driving faster than we want them to, then we need to redesign the street, rather than letting the tail wag the dog. There’s something wrong with our street design if you’re getting 85 percent of our motorists to drive 10 miles an hour faster than is safe for the conditions.

The report sets the platform for creating that livability. It covers the planning aspects, it gets into the broad-based principles and then it gets down to the exacting details and explains why 10-foot and 11-foot lanes are superior to wider lanes. It gives more flexibility while providing specific language that an engineer and a planner could pull for their own street standards.

: How do these guidelines and recommendations get turned into change on the street? Where does the federal government come in? The state and local governments?

: First of all, there’s always been a misunderstanding about federal standards. It doesn’t matter what state I go to; I can hear some folks in the state agency say, "Well we have to do this, because the federal government says that these are the standards." The federal government does not set standards. They help create publications, they provide a lot of guidance, but they truly have no desire or ability to set the standards that a local government would impose.

The key is influencing those in state government to realize that they’re in charge, that whatever language they create can then be inserted in a local street system that happens to involve state funding. In some states, the total street system, from an alley to a lane to an arterial, is set by state guidelines. In Florida, we have what’s called the Green Book committee; I used to sit on it for about 15 years. We came up with guidance for what every category of road would be and then whoever built the road — certainly any private developer — had to follow those standards if they wanted to turn the road over to the community. They gave a baseline for certain margins of safety and performance.

"The clear zone that’s required — how far you have to set back trees or other fixed objects from the roadways — was determined years ago by one phone call from a committee of AASHTO to the General Motors test track."

The problem of having standards that every community in the state must follow is that it doesn’t necessarily give the best level of flexibility. If a community writes their own street design guide, then they can totally revamp: They can come up with flexible streets, curving streets, living streets, all the terms we’re now using. So it becomes imperative to get street making down to a local level. You still need to be predictable at a state level, though. This guide helps give the language that a local community might need to narrow streets or provide a different level of street connectivity. That’s something that needs documentation.

: So are you arguing that states should take a step back from transportation planning and let local governments move in?

: Yes I am. I feel that the people who end up populating the committees that set these standards are not keeping their ears close enough to what’s going on in a given neighborhood. By the time you’re high enough up in the chain of your state agency, you no longer go to public meetings, you no longer read every document that comes out. So you’re trying to make decisions that are good for everybody, even though you’ve reached a point in your career when you’re no longer grassroots.

: What does that detachment lead to?

: You feel like you have a responsibility to keep raising the bar but in many cases the bars gets raised with absolutely no scientific evidence. For example, the clear zone that’s required — how far you have to set back trees or other fixed objects from the roadways — was determined years ago by one phone call from a committee of AASHTO to the General Motors test track. So they’re talking to one person at the test track — for cars — and the guy said 100 feet and [AASHTO] said, "No, that can’t work, we can’t buy 200 feet of right of way everywhere." So they negotiated and said 60 feet would eliminate a lot of the crashes. That’s how they determined it. If you went back and studied how a particular measure came to be, it’s, "OK, if I agree with you it should be 15 feet rather than five, then will you agree with me on my point about this topic?"

Context_Street_Plan.pngThe CNU/ITE report is context-specific: What’s next to the street should influence the design of the street itself.

: In terms of the internal politics of state departments of transportation, is there some sort of bias in how the roads are designed?

: Historically the AASHTO Green Book, which is still what most people will quote and many state design guidelines are built around, is built for rural America and for suburban America. It was never designed for downtowns. It was never designed for the average neighborhood street. It was designed for this new America we were building, where we wanted to keep the greatest flow of vehicle movement. So we come up with things like turning radii on the corner of an intersection, driveway flows, everything based on a suburban and a rural application.

: Do you think that momentum toward livable streets — among both engineers and the state departments of transportation — is going to continue?

: I know it’s going to continue. For example, take complete streets. Every state that adopts a complete street philosophy now comes together to try to figure out, well, What does this really mean? So it builds on itself. I was in Columbus, Ohio, where the state has adopted a complete streets package and now everybody is quickly trying to figure out, Do we always have bike lanes or do always have this or that? So, yes, I think that, along with Secretary LaHood’s recent comment that pedestrians and bicycles will have equal considerations in designing and building and funding our streets, that this is shaking up the industry.

Obviously we’re crafting new buzzwords and we’ve got more enlightened secretaries of transportation, but we’re also going to realize we cannot continue to build roads that are not sustainable. They create more drainage impacts, more heat gain, more use of oil for asphalt or processing concrete. These resources are going to put us in a non-compete situation with the rest of the world where we’re just trying to keep our system working. In many cities now the individual is spending 20 percent, even 25 percent, on their transportation out of their take-home pay. That’s not sustainable at a personal level.

  • Guy on Bike

    DOT’s parking protected, curbside bike lanes are much better than what’s shown above. They keep you out of the door zone, and safe from parking movements, double parked vehicles and cruising traffic. The only place this design works is in a low traffic downtown — which is probably dead by definition. They need to do much better.

  • The bike lanes in the illustrations look terrifying: the top and bottom have cyclists firmly in the door zone, while the middle one shows a right hook in action.

  • Seriously. Bulb-outs are great, but you can integrate the bike lanes to go over/through them so they stay curbside. That space then becomes double-use for both.

  • MtotheI

    I agree with the other commenters. This is not super exciting or ideal.

    Just to add to the discussion, in urban environments that foster walking, it would be nice for crosswalks to be raised to sidewalk level so that when vehicles cross through they are very aware that they are entering pedestrian space. Otherwise pedestrians must enter car/truck space which creates lots of accessibility and safety issues.

  • patrick

    I believe the picture with the right hook is an example of what not to do. In this situation I believe the appropriate move would be to make the corner more of a right angle instead of the curve as pictured.

  • I’d have to see this intersection in person, but saw it on Portlandize and thought it applies.

  • Oh, and another thing – the traffic lights are still very high and large, on an automobile scale. In many European cities, the lights are lower, which keeps drivers’ eyes trained lower on the street, paying attention to what’s on it. Not only that, but I believe they’re less costly as they’re smaller – check out this highway, for instance:,+8200,+Aarhus+Municipality,+Denmark&ll=56.193191,10.186901&spn=0,0.038581&z=15&layer=c&cbll=56.193269,10.186852&panoid=IunffPxnSvhf4QNurrhT0Q&cbp=12,157.57,,0,12.11

  • Actually Aaron, look no further than DC or Boston for stoplights placed on the sides lower to the ground.

    Unfortunately it appears that some kind of federal change came into affect in the last decade banning them. When redoing a street, Boston has been eliminating the black stoplights on the side to silver overhead ones, and citing federal guidelines.

  • icarus12

    First off, I love all this wonky stuff from real engineers about street design, so thanks for having it on the blog.

    I am hoping that as we do go about redesigning streets, we don’t adopt a one-size fits all approach to every street within a single city like San Francisco. I think there should be several arterial streets running North-South and several more running East-West such that a car driver can travel through the city at 30 mph on timed lights without doing crazy things like speeding beyond that or honking our damn horns or jamming through on amber lights. As a mostly biker and pedestrian, I am fine with that as long as I get lots of pleasant options. Options like lots and lots of parallel routes exist that arend relatively flat and scenic. For example, I love taking Valencia on my bike and Guerrero when traveling by car, but I hate getting stuck on Folsom in the Mission. Folsom serves nobody properly — it’s dangerous to bike there and it’s a frustrating stop&go drive. Everybody just ends up frustrated no matter what their mode of transportation.

    It just doesn’t make sense to define the new urbanism movement as hostile to cars. Better to make it a movement grounded in the reality that the same urban resident likes to move around at different speeds in different places for different purposes using different modes of transportation. Make mobility something for all and give us the variety options we gravitate toward anyway.

    Maybe this is what wonky New Urbanist engineers and designers are doing already, and I just have the wrong impression based on what I hear from community groups that want the traffic in their own neighborhoods to magically slow down or go away. Thoughts, readers?

  • I don’t think it’s meant to be defined as “hostile” to cars. However, I believe urbanism to be about making our cities attractive, safe, and livable places, and too many cars works severely against that ideal. And it’s also about, like you’re saying, creating more equal transportation options – but if the status quo is cars detrimenting the appeal of other modes, which they certainly are, then they are going to have to give up space and slow down. But with our American cities favoring cars to such a ridiculous extent, the changes could seem “hostile” to cars for some.

  • chris

    I know several of the comments have touched on this, but why are physically separated bike lines not catching on? What kind of idealized vision of a street wouldn’t include one? Or, second best, a bike line between the line of parked cars and the sidewalk (with room for door openings). It seems soo simple and cheap but it seems like asking for a high speed rail line.

    I regularly rode on a bike lane like this for a year in Spain and it seemed ideal. Low cost–just restriping. I’ve seen this is several different countries but sadly never in the US. And not in the Bay Area or Portland in any serious way, two of the supposedly most bike friendly places here.

    Pretty sad.

  • Dan Burden is the man! He’s been fighting the good fight since most of us were sucking our thumbs and wetting our diapers!

    Great Interview and very informative! This is definitely one of the best stories in Streetsblog in some time!

  • Wait a second – if the guideline says that the design speed should be such that only 15% of drivers will drive faster than it, then why does it imply 85% of drivers are driving faster than we want them to?

  • ok, good start! However that is a poor design for anything but 20mph streets, and at that level there should be no bike lane but sharrows that give cyclists priority in the road. Otherwise if you have the space, and it looks like they do in this example, lets go for the separated cycle tracks and do it right. Make the sidewalk bulb-outs true and run the track through the crosswalk area, with signage to watch for cyclists. We are getting there though and I applaud the effort!!. I also want to know why the very high overhead lights which make people look up and not at the actual traffic or pedestrians or cyclists… I never thought about it but they are a problem for sure! Somebody needs to find out where its being mandated (if it is) and work to get that changed…

  • Robin

    separated cycle tracks only aggravate the safety hazards created by bike lanes by taking cyclists out of the motorists view. The are not unbroken paths so the cyclists appears suddenly at the intersection to the right of a motorists leading to right hook accidents. They also prevent a cyclist from asserting themselves and moving to the left to make a left turn. Stop worrying about separating uses in the travel lane. Accidents happen at intersections. The only a appropriate redesigns for the travel lane are efforts to calm traffic to speeds of less than 20 MPH in all urban zones. This speed is proven to reduce fatalities substantially.

  • Robin, have you seen NYC DOT’s new cycle tracks on 8th/9th Ave and Grand St? They address the right/left hook problem in two ways: 8th/9th Aves have separate signalization for motorists turning across the cycle track; Grand St has “mixing zones” where there’s no parking and there’s extra visibility. In my experience, both treatments are very effective. (It helps that Grand St traffic naturally moves fairly slowly because it’s a narrow street.)

  • Mike, I’ve ridden and photographed the NYC cycle tracks you mention. They put a lot of work into the design, and I respect that — but at the end of the day, they started with a bad paradigm and got a result with significant flaws.
    First of all, if you ride the cycle tracks and actually obey the signals, your average speed will be extremely low — If I recall correctly, we averaged barely 6 mph on Grand Street. This leads to two non-startling conclusions: New Yorkers will not obey the signals, and the cycle track is so slow as to be useless if you do obey the signals.
    Second, the cycle tracks don’t allow easy access for turns or destinations on the other side of the street.
    Third, the complexity of a cycle track leads to added complexity to try to fix it. The number of signs at intersections is mind boggling. If anyone thinks that any motorist or bicyclist can read all those signs, absorb the information, and respond appropriately while driving/riding at 5 to 20 mph, I say “good luck with that.”
    You can see photos of the signfest and a video of our 6 mph ride here:
    Among the users of the cycle track we observed that day, wrong-way riders and skateboarders outnumbered people headed in the correct direction. The cycle track was frequently blocked by delivery hand trucks, construction equipment, and pedestrians (who were — surprise — oblivious to bicyclists).
    I understand why New York residents want separated facilities. The streets are mosh pits of aggressiveness. But the best answer isn’t to accept the aggressiveness and hide from it on a problematic cycle track. The best answer is to make the aggressiveness socially unacceptable, so the streets aren’t intimidating. That describes the community where I live, 100 miles west of New York. It can and should describe New York — and every other community — too.
    There are places where we need street design changes (I agree with some changes, disagree with other changes), but first and foremost we need behavior changes — and we don’t spend nearly enough time talking about that.

  • That street design is such a waste of space, but I bet it makes the more compromised Complete Streets people happy.

  • Mike Epstein

    There is a speed issue on 8th/9th, but there really isn’t on Grand St. I routinely turn onto Grand St at Thompson St, ride a solid 12-15 mph, make the light at Broadway, make the light at Bowery, and get to Chrystie Street with no major stops. (Occasionally I miss the light at West Broadway, but that’s not a big deal.) I’m not sure what was slowing you down. There aren’t a lot of right-turning cars off Grand.

    “But the best answer isn’t to accept the aggressiveness and hide from it on a problematic cycle track. The best answer is to make the aggressiveness socially unacceptable, so the streets aren’t intimidating.”

    And I want a puppy that wears a unicorn hat. Good luck.

  • Mike Epstein

    John, I just watched your video. It was shot when the lane was still very new and people were getting more confused. Compliance has improved noticeably of late and there are fewer obstructions (except for the block between Bowery and Grand, which is a mess).

    Also, I think you guys rode very timidly — once people get used to the lane and get used to where obstacles and hazards can come from, they can safely ride a bit faster.

    My last point: don’t underestimate the value of a relatively safe way to get crosstown at 6mph. 6mph is actually a pretty great all-in speed for a crosstown ride in Manhattan. Because of signal timing and weaving around double-parked cars, most other routes are as slow or slower, as well as more dangerous.

  • Mike Epstein

    p.s. there’s no merging area at Bowery because all turns are banned there. That rule was new when you shot the video and it took a while to be observed. Compliance with that has also improved of late.

  • Ffolz

    The high overhead traffic signals are the paradigm from the MUTCD. The idea is to make traffic signals very visible on high-speed approaches. I agree that they are totally inappropriate for close-in urban streets with low speeds and multiple kinds of road users. The size of the signals is pretty much determined by how high they are from the ground. The current MUTCD is trying to get rid of the 8 inchers.

    When I was in engineering school my professor challenged us to find “MUTCD violations” in the Boston area (which is pretty trivial) and I think that exemplifies the mindset. “This is the handbook; we should build to handbook.” Absolutely NO critical thought as to whether the handbook makes a lick of sense in context.

    I completely agree that the high and away signals are inappopriate and dangerous in the close-in urban context. I would much prefer a small, lower to ground signal that I could actually freaking see. Honestly, I when I was an urban bus driver I stopped looking at traffic signals at intersection and only looked at the traffic (&peds, etc). This got me in trouble once or twice for proceeding at red when the intersection was clear!

  • Claire Vlach

    I’m a little late to the discussion, but I want to address some of the comments regarding the illustration at the top of the page.

    Mainly, I would like to clarify that the drawing was never meant to illustrate an ideal street, and is not meant to function as a “template,” as suggested by the Streetsblog caption. Rather, the purpose of the drawing was to illustrate how a street differs from other thoroughfare types, such as an avenue or boulevard. (A discussion of the different types of thoroughfares and their functions within the transportation network can be found on pages 48-53 of the report; a free PDF can be downloaded at .)

    For an example of how street design is affected by different levels of government, see the draft “Multi-modal Access Strategy & Context-Sensitive Design Guidelines” for El Camino Real on the San Francisco Peninsula (A link to the PDF is available at ). These recommendations for multi-modal improvements to an urban state highway are intended to help local communities make street design improvements, while staying within the current Caltrans state standards.

    Finally, to address a few specific points:

    @ icarus12: I think that the discussion of the different types of thoroughfares I mentioned above addresses your point about different routes accommodating different primary modes of travel.

    @ Mtothel: See page 154 of the report for an example of a raised crosswalk as recommended at a mid-block crossing.

    @ Aaron Bialick: Regarding the traffic signals… yes, they are very high and large. Ideally, they would be smaller and nicer. However, since the drawing was aiming for typical rather than ideal, I let them be. Additionally, it can easily cost upwards of $100,000 to replace a traffic light, and you can make a lot of potentially more significant improvements for $100,000.

  • Filamino

    The overhead signals over the roadway make the signal more visible to drivers, particularly on multilane streets. When there are buses and other tall vehicles are next to drivers, it’s hard to see the lower side signals. When this happens, it results in tragic red light running accidents.

    I don’t see the bigger signals on the 2-lane streets that people are claiming to see around the City. If so, it’s very rare. I don’t believe the arguments here that they distract the driver from watching for pedestrians. Why should they be looking for pedestrians crossing in front of them if drivers are going straight on a green light? Preventing red light running is much more important.

    @Aaron-the link you have shows exactly what signal configuration we have here in the City. The streetview picture shows an overhead signal with signals on the side, so we are already like many European cities in regards to signals!

  • Aaron Bialick

    @Robin & others, in regards to cycle tracks –

    They are not inherently problematic. I’m currently living in Denmark (that’s why I chose that place to link) and most streets in the cities have cycle tracks. If Copenhagen isn’t proof of their success, then I don’t know what is.

  • Things would be a lot simpler if the folks designing the streets would spend some time using the intersections and bike lanes as a pedestrian and a cyclist, and take one of their kids or grandchildren along with them.

  • Tim

    In Copenhagen,(where I have also ridden) they have scientifically evaluated their cycle tracks and they have shown that while they feel safe, and attract more cyclists,they are actually much more dangerous at the intersections. This is due in part for the reasons mentioned above by Robin. Separation works well in some situations but not when the cycle track crosses intersections and driveways.

  • The above comment is misleading. First of all ‘much more dangerous’ is a gross exaggeration. The stufy that analysed the situation at intersections did find an increase in accidents. It is worth noting that this included accidents where cars rear-ending each other at low speeds.

    The result of the study can be seen all over Copenhagen. We’ve pulled the stop line for cars back 5 metres at over 120 intersections. We’re implementing bike boxes. We are increasing the ‘pre-green’ for bike traffic lights – meaning that the bike traffic lights turn green between 2 and 10 seconds before the lights turn green for cars.

    At busy intersections the bike lanes often sweep to the right, completely separated from the traffic flow.

    All of these initiatives have already proven to be successful in making the safe, separated infrastructure even safer. At Denmark’s previously most dangerous intersection, with 15 serious injuries at year (worth noting that there are over 60,000 cyclists a day crossing this intersection alone), the number of serious accidents has been reduced to one (1).



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