The Diverging Diamond

A couple of weeks ago, I ran a short blurb in a Friday News Digest about the idea of a diverging diamond interchange. Here's what I said:

Speaking of videos and engineers, did we need more proof that the engineering profession is insane than this video of the "diverging diamond". If we had infinite resources (we don't), this would still be crazy, but the fact that we're broke just shows you how insulated from reality so many of them are. Hey, engineers -- watch my TED talk on the difference between a ROAD and a STREET. You're trying to rid yourself of accident-prone left turns? Well, how about just build ROADS where there is no need for left turns and STREETS where they are no problem, instead of the STROADS you build today. I'm not joking.

There were some hard feelings in the comments section about my categorization of the diverging diamond -- and the egineering profession that developed it -- as insane. In a spirited discussion, one of our readers posted a video of an engineer giving an enthusiastic tour of the pedestrian features of one diverging diamond. For me, it was irresistible.

The following video is my "response". Sometimes I feel as if I'm shouting into the wind with the engineering profession. This may just be more of that. If nothing else it was theraputic to me. Hopefully it provides some value and insight for our readers.

As a final note; while I acknowledge that I did pick and choose the comments of the enthusiastic engineer that I wished to highlight, I did not edit the video or his comments. I don't think I took any out of context either. Please listen for yourself and see if you agree with my "insanity" assessment.

Co-opting Complete Streets

The idea of a Complete Street is compelling in almost every way, but when the engineering profession begins to adopt it wholesale, we need to pause and look at the outcomes. Are we getting Complete Streets, or are we getting Complete Roads. The difference is tremendous and will impact the financial viability of an approach to building places that is long overdue.

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The Complete Streets concept is one that is long overdue. We've spent two generations transforming a public realm once comprised of walkable, mixed-use neighborhoods into auto-only zones. These are places where the kids used to play ball in the street. Today a kid can't even play safely in their own front yard.

At Strong Towns, we've worked to illuminate the fact that this transformation has been done at tremendous financial cost. This is not only because the construction of wider, flatter and straighter streets has been expensive, but because the auto-centric nature of the transformed public realm drives private-sector investment out of traditional neighborhoods, dislocating it to places that provide more buffering to the car.

Not only that, but the redevelopment that has happened in these neighborhoods has largely been on a suburban framework, using the parking ratios, setbacks and coverage restrictions of modern zoning to reduce density (and the rate of return). Financially, these places are largely insolvent, lacking the tax base to maintain their basic infrastructure.

Enter the concept of a Complete Street. To me, the fundamental contribution of Complete Streets to the discourse surrounding the future of our towns and neighborhoods is the recognition that our streets must serve more than just cars and that the public realm can no longer be an auto-only zone. The fact that the Complete Streets model has broken the stranglehold that the auto-only design mentality has had on our streets should be the cause of unending rejoice.

In March I was able to have dinner with Kaid Benfield. During the course of our conversation, he enlightened me on how the Leadership in Energy and Environmental Design (LEED) standards were tweaked with Neighborhood Design principles. The result, LEED-ND, takes a great concept -- buildings that are energy efficient and environmentally friendly -- and overlays it on a development framework that reinforces these principles. In other words, no more "green" buildings in the middle of a greenfield, with 30 mile commutes each way.

In a similar vein, we're going to now, humbly, suggest a way in which the Complete Streets concept can evolve to achieve what I believe is its principle intent, that being Complete Neighborhoods. 

I've now seen two projects where engineers promoted the use of "complete streets". In each I see the engineering profession co-opting the Complete Streets moniker without any thought to a Complete Neighborhood. For the engineers on these projects, the approach remains the same. I'll quote from our piece, Confessions of a Recovering Engineer:

An engineer designing a street or road prioritizes the world in this way, no matter how they are instructed: 

1. Traffic speed
2. Traffic volume
3. Safety
4. Cost

The rest of the world generally would prioritize things differently, as follows: 

1. Safety
2. Cost
3. Traffic volume
4. Traffic speed

In other words, the engineer first assumes that all traffic must travel at speed. Given that speed, all roads and streets are then designed to handle a projected volume. Once those parameters are set, only then does an engineer look at mitigating for safety and, finally, how to reduce the overall cost (which at that point is nearly always ridiculously expensive).

One of the places I've seen Complete Streets applied is My Hometown's Last Great Old Economy Project (also known as the College Drive project). In this instance, the design starts with a minimum design speed and a projected traffic volume, the latter being the stated impetus for the project. This analysis provides us with four lanes of fast-moving traffic. The engineers then move on to the "safety" criteria and the mandate that -- if we can afford it -- we accommodate bikes and pedestrians. This is done, of course, at tremendous cost - estimated at over $7 million for a mile of road.

Now notice that I called this route a "road" and not a "street". Understanding the difference between a road and a street is critical to understanding the problem we have with engineers misusing the Complete Streets approach. From our Placemaking Principles for a Strong Town:

To build an affordable transportation system, a Strong Town utilizes roads to move traffic safely at high speeds outside of neighborhoods and urban areas. Within neighborhoods and urban areas, a Strong Town uses complex streets to equally accommodate the full range of transportation options available to residents.

Roads move cars at high speeds. Streets move cars at very slow speeds. We should build roads outside of neighborhoods, connecting communities across distances. We should build streets within neighborhoods where there are homes, businesses and other destinations. The auto-road is a post-WW II replacement of the rail-road. The street should be what it has always been; the street.

The fundamental design flaw of the post WW II development pattern -- the false premise upon which every other design tragedy has been committed -- is the transformation of our streets into roads.

High speed auto travel has no place in urban areas where the cost of development demands a complex neighborhood pattern with a mixing of uses, multiple modes of travel and a public realm that enhances the value of the adjacent properties. High speed traffic destroys value in our neighborhoods. It drives out investment. There is no amount of pedestrian enhancement that we can build to offset the negative response people have to being in the close proximity of speeding traffic.

Without aggressive traffic calming -- which is part of the Complete Streets playbook -- we will simply be building Complete Roads. A Complete Road will not transform the public realm, no matter how much money we put into accommodating pedestrians and bikers with bridges and tunnels. A Complete Road will not attract significant private-sector investment in the key neighborhoods where we have so much existing infrastructure liability. And a Complete Road will cost a fortune, without changing the insolvency problem facing our cities.

If there is one thing our current financial situation should teach us about the engineering profession it is this: engineers will bankrupt us if given the chance to build our cities and towns the way they envision them. It is predictable that the engineering profession will embrace the concept of a Complete Road -- which is nothing more than a bad design made PC by throwing an expensive bone to bikers and pedestrians -- because it fits with their hierarchy of values (speed, volume, safety and then cost). Insidiously, promoting Complete Roads will ensure them more funding than they would otherwise receive. You can call them "streets" all you want - unchecked, they are going to build "roads". (For example, check out the 14-foot highway lane widths on the Complete "Street" cross section on My Hometown's Last Great Old Economy Project).

We love Complete Streets. They are essential to a Strong Town. Let's get out there and build them, but make sure the engineers don't con you into a Complete Road. Demand slow cars and a Complete Neighborhood to go along with your Complete Street.

Additional Reading

• National Complete Streets Coalition

• Confessions of a Recovering Engineer (November 22, 2010)

• Video: Conversation with an Engineer, Street Project 

• Where the money went (July 19, 2010)

• We spent how much to get what? (August 4, 2010)

• News Brief: Streets we can't afford (September 8, 2009)

• Better Looking Streets (Cheaper too) (January 12, 2010)

Earlier this year we started collecting donations to cover the cost of producing a DVD version of the Curbside Chat. Our goal was to connect with 100 of our readers that would be willing to donate $25 each. We've taken quite a bite out of this so far -- we've signed up 35 -- but we still have a ways to go. If you value what you read here or what we produce in our podcast, please do what you can to help us spread this message. We thank you, especially if you are one of our 880+ Facebook connections! It was only a year ago we were still below 200. Thanks for spreading the word. 

Friday News Digest, Spooky Version

My wife and I have not historically been "Halloween people". We started dating in high school and, even then, we weren't ones to dress up and go out. I played drums in bands for many years (yes, I used to be kind of cool) and we did a lot of gigs on Halloween, but these were audiences not gathered to hear music and so they were not my favorite bookings. Today everything is different. With two little girls, Halloween is one of the big days of the year. We've spent a month preparing our "Wolf" and our "Giraffe" to get out and fleece the countryside of candy, the vast majority of which we will never let them consume. When my youngest's giraffe costume arrived I thought she was going to explode with joy. Me too, actually.

I hope your weekend is filled with spooky and good fun. Enjoy the week's news:

• Our friend Jake Krohn over at Basement Office has featured some Strong Town's content on his site. We wanted to say thanks for the referrals and also for your contributions to the cause. I still have Wahpeton on the list for a Curbside Chat, although it almost made me cry to see how they rebuilt Dakota Street in honor of their cars. We'll connect after elections reset the map.

• This is a post from last July (not sure why it was flagged on my list this week), but it is still more than timely. Melissa Lafsky at The Infrastructurist suggests that cities should be run like software. Yes. Part of improving local governments will include empowering the citizenry to be more directly involved in day-to-day decisions. Think of the old Sunday meetings in the town square, only now using modern technology and connectivity. We don't need great individual leaders at the local level when we are all empowered to bring about change.

In fact, with the right framework... we might be able to create a sort-of operating system for cities — a system that closes the loop between the “eyes on the street,” the problems they spot, and the authorities charged with responding to them. It could have features like a prioritization algorithm, an open-ticket system that will incentivize speedier action (think the tickets you file to the IT guys in your office) and even a layer of data analytics and visualization. Plus there’s the possibility of eventual automation of the problem-reporting process — think streets that tell you when a new pothole is forming.

• Politicians trying to create jobs and induce growth would do well to read an article from nature.com about Building the best cities for science. I find it interesting that the suggestions for scientists really would apply to any city looking to be a hub of innovation. These are some recurring themes for the New Economy.

From case studies, Mary Walshok, a sociologist at the University of California, San Diego, picks out three important factors that make cities sticky for scientists. Promise them the freedom to work on their own ideas. Then give them the tools and infrastructure to do so. Public funding is key to achieving these first two aims, but local private corporations and philanthropists who endow new buildings or research chairs also help. "You can see this happening in Austin, and in Seattle," says Walshok.

Walshok's third factor is an attractive lifestyle. Richard Florida, a sociologist and economist at the University of Toronto's Martin Prosperity Institute in Canada, lists scientists among the 'creative class': mobile, talented, creative thinkers that a city must lure in with amenities and smart urban planning.

• Earlier this week I alluded to some disconnect we have with the Complete Streets approach. I was not able to get back to that as events overtook life, but, in brief, I question the efficacy of imposing a trail on every roadway, regardless of that roadway's function or the return on investment. I've seen miles of trails and sidewalks built with no context to the neighboring land use, neither serving anyone nor connecting anything. Complex streets are a necessity in a city seeking to be a Strong Town, but it should really not be surprising to anyone that building a trail near a simple roadway (a suburban section that lacks urban complexity) provides no substantial benefit to individuals or society. (We love Complete Streets.....Complete Roads we can easily live without).

One unique aspect of the study was its “before-and-after” approach — it measured the neighbors’ walking-jogging-cycling frequency before the trail was built and after it was completed. About 87 percent of those who used the new trail reported they were pursuing these activities before the path was constructed and used sidewalks or more distant trails. Proximity to the trail had no significant effect on total physical activity; those near it were no more likely to use it than those farther away.

• I read a blurb somewhere this week about home ownership rates in the US and Canada. It noted that Canada had comparable -- or even higher -- rates of home ownership without the sacred deduction. Canadians just had smaller homes. So this big subsidy has not gotten us an "ownership society" as hoped, it simply got us bigger houses (to go along with our bigger girth, I suppose). I love Marianne Cusanto's work on "small" homes and so was excited when it was discussed prominently in a NY Times article on The Elusive Small-House Utopia. Check out her website if you want to see some beautiful architecture that I hope will experience the resurgence she is seeking.

When Cusato sat down to devise the Home for the New Economy, she tried to consider how families actually use their living areas. She started with a simple, symmetrical three-bedroom plan, excising extraneous spaces — the seldom-used formal dining room, for instance — while enlarging windows wherever she could and adding a wraparound porch. A result was a house that was compact, comfortable, bright and energy-efficient.

• At Strong Towns, we are trying desperately to wake up the country to the destructive nature of our land use policies and decisions. My particular passion is that of small town and rural America. I'm worried about the future of these fragile places, especially if the status quo toolbox continues to be the only approach of the establishment. But I'm also optimistic because I know that an empowered populace, working together in their own communities, can do amazing things. It was reassuring to find out this week that 87% of my neighbors feel the same way.

The study found a sharp increase in the number of rural Minnesotans who believe their communities are struggling. The study found that 37 percent believe quality of life in their community has declined, four times what it was 10 years ago when 9 percent of respondents felt that way.

But the study also found 87 percent are confident that they can help their community become a better place to live. Nearly seven in 10 are confident quality of life will improve over the next five years.

"The health of rural Minnesota is essential to the health of our entire state," said Jim Hoolihan, president and CEO of the Blandin Foundation. "Rural Minnesotans are struggling to maintain jobs, schools, and checkbooks - and yet have confidence about the future of their communities. Their challenges and assets must be part of the discussion - and a part of the solution - in virtually all matters relevant to the future of Minnesota."

• And finally, if you see any of these kids show up at your door Sunday night, don't be scared. Just hand over the candy and then back away slowly. My Chloe is the wolf in the front row (second from the left) and my Stella is the giraffe in the back (far right). The rest are cousins and close friends - ten girls total. Twenty years from now we'll do nothing but go to weddings, but for now we trick or treat and smile the whole time. Stay safe, everyone.

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