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Seeking flexibility amid the invisible hand of street design standards

If you go into any transportation office in the state, you’ll find somewhere a shelf filled with thick books of standards and guides. They offer an alphabet soup of acronyms: MUTCD, AASHTO, NACTO, ITE, CNU, the “green book,” and dozens of smaller municipal design guides. Each of these sets of standards can limit or shape how a city street is built. As a few different engineers explained to me, they act like tools in the engineering toolbox, providing cities with ideas and models for their streets.

MinnPost photo by Bill Lindeke
The MUTDC, or official Manual for Uniform Traffic Control Devices

But not all standards are created equal. Some have more influence than others, and which standards a city uses can make a huge difference for how our cities look and feel.

Earlier this year the public works departments of Minneapolis, St. Paul and Hennepin County joined with the state Department of Transportation (MnDOT) to officially endorse the NACTO Urban Street Design Guide, becoming only the fifth state in the country to support to new the engineering manual. NACTO is short for the National Association of City Transportation Officials, and it has for years served as a more flexible set of designs that larger cities around the country can use for more dense urban environments.

“In the NACTO book they include interim designs,” Jon Wertjes explained to me a few weeks ago. Wertjes is the director of Traffic and Parking Services in Minneapolis’ Public Works Department. “NACTO really says that not everything needs to happen because you’re reconstructing the street. Instead, there are some elements that are low cost in the book, to help the goals move forward without having to move a curb.”

Similarly, the NACTO guidelines offer innovative designs that do not yet appear in more common engineering standards, such as the “AASHTO green book” used throughout the country. (The acronym AASHTO stands for  the American Association of State Highway and Transportation Officials.)

“NACTO does matter,” explained Ethan Fawley, executive director of the Minneapolis Bicycle Coalition. “NACTO offers guidance for building protected bike lanes, and as advocates for protected bike lanes, it matters a lot for us. AASHTO standards don’t yet include protected bike lanes, and the fact that MnDOT has endorsed NACTO gives extra comfort for working engineers wanting to have the best practices in urban environments.”

Adhering to standards in engineering culture

For lots of great reasons, the field of engineering is closely aligned with standards. They ensure that streets are uniform across the state, and are built to handle certain volumes and weights of traffic. But the way that standards work with actual on-the-ground designs seems to be changing.

Charles Marohn is a professional engineer who practices in Brainerd, Minnesota, and founded a nonprofit group, Strong Towns, aimed at changing how cities are designed and built. For Marohn, Minnesota’s official “State Aid Standards” are a big problem for cities and towns. They require a rigid adherence to high-speed designs for any road receiving state money, meaning that streets across the state are overbuilt with wide lanes that are often unnecessary, expensive and unsafe. 

“State Aid Standards are to me the most destructive thing we have right now for cities,” Marohn told me. “Whether it’s a street improvement, congestion, or an intersection with safety problems, we literally turn around and go to a manual and look up what should be there. It seems from the outside like there should be more thought than that, and you should actually go out and study the intersection and do a design. But right now, thanks to State Aid Standards, it’s as rote and as dumb as that.”

Photo by Charles Marohn
A sign begs drivers to slow down while the design of the street itself sends the opposite message.

Marohn’s concerns closely mirror those of Ethan Fawley, who points to how the State Aid Standards force cities to spend time and money widening roads or receiving exceptions. For example, with few exceptions, Minnesota’s State Aid Standards require 11-feet-wide drive lanes and 10-feet-wide parking lanes, while the national AASHTO standards allow 10-feet and 7-feet-wide lanes respectively.

“It makes a big difference in our ability to provide wider sidewalks, to calm traffic to add a bike lane or a boulevard tree,” Fawley explained. “We want to spend less money by having a road that is the right size for the right context. All these things are impeded by State Aid Standards, and it’s something that has so much impact over last couple of generations.”

Real-world choices

For example, Fawley described how in Northfield, Minnesota, state standards required that a 70-year-old street be expanded from 36 feet to 38 feet. Those rules meant either the removal of crucial on-street parking or a time-consuming variance process. (The city of Northfield decided to go for the variance, and received it after a few months.)

Likewise, according to Fawley, when the City of Minneapolis wanted to change South Lyndale Avenue from a four-lane to three-lane street, Hennepin County engineers were reluctant to approve the plan because it violated State Aid Standards. (The change finally took place after a 10-year delay.)

“The research certainly does not prove that there’s a correlation between lane width and safety on these lower-speed streets,” Fawley told me. “Often what happens with wider lanes is that people drive faster or pay less attention. Research does not show that there is a difference in safety. Instead, there’s a tot of evidence to suggest that we spend a lot of extra money and extra time.”

Photo by Charles Marohn
Willow Street, an official “State Aid” road, is built extremely wide despite being a low traffic residential street.

Increasing local flexibility through design guides

Like most engineering problems, figuring out how to solve the problem of engineering standards is complicated. Fawley suggests changing Minnesota law so that cities would be able to “opt out” of using rigid state standards.

On other other hand, Marohn believes that Minnesota should simply do away with the State Aid system altogether.

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“I would eliminate the entire State Aid system,” Marohn told me. “It’s broken and I would get rid of it tomorrow. We would be much better off. If state government still wants to fund local transportation projects, I would do that with block grants. We have licensing for engineers. They are intelligent people, and they can figure this out. Let’s leave design to local officials, to do what is best for their community.”

But any change to State Aid Standards would have to happen at the state level, where Sen. Scott Dibble heads the Senate Transportation Committee.

“State Aid Standards are ensconced in rule and hard-wired,” Dibble told me this week. “There’s no reference to a design manual, and so I’m interested in figuring out how we can crack that nut and allow for references to other design criteria and design priorities. I don’t know exactly how to go about it, but AASHTO is no leading edge. It’s the professional organization of commissioners of transportation, headed up by engineering professionals.”

NACTO provides a more flexible set of designs for more dense urban environments.

Meanwhile, public works departments in Minneapolis and St. Paul, and in counties throughout the seven-county metro area, are still working on developing new design guides. In addition to the recently adopted NACTO design guide, Minneapolis adopted its own city design guide in 2008, called Access Minneapolis.

Likewise, across the river, the city of St. Paul is developing its own citywide “Saint Paul Street Design Manual.” The new guide will outline city designs for streets that accommodate all users, including pedestrians and bicycles. (The new manual will go through review by neighborhood groups and city officials before being officially adopted later this year.)

But these new design guides are only successful if they are used in the real world. For State Aid roads, which run through every city and town in Minnesota, it remains very difficult to built a roadway exactly the way cities want to. With NACTO, “Complete Streets,” and a host of other guides, cities will have more tools in their toolbox. It remains to seen if they’ll be able to use them.

Comments (14)

  1. Submitted by jody rooney on 07/29/2014 - 10:43 am.

    That’s interesting

    any thought to using the already existing trail guide published by FHWA as a base?

  2. Submitted by Matt Becker on 07/29/2014 - 11:41 am.


    This might explain at least some of the poorly designed streets in the city of Roseville.

    Take Fernwood Ave, for instance, a not-so-major north-south route that connects County Rd B to Larpenteur. It’s a residential street with homes on both sides, but it screams for high automobile speeds while not being the slightest bit pedestrian or bike friendly.

    It was just repaved with fresh lines south of Roselawn Ave this summer, but instead of adding a bike lane, they just repainted the same ultra wide lanes and ridiculous parking lanes (ridiculous because everyone on the street has a driveway.)

    • Submitted by Bill Lindeke on 07/29/2014 - 01:07 pm.

      “state aid” streets

      I’m not actually up on which are “state aid” streets and which aren’t. The criteria seem very complicated, and you’d have to ask a local engineer most likely.

  3. Submitted by Diane Spector on 07/29/2014 - 01:33 pm.

    State Aid Streets

    State Statute allows municipalities over 5,000 in population to designate up to 20% of their lane miles as “State Aid Streets.” There are also County State Aid Streets. These streets are supposed to be collectors and interconnected within the city and to other state aid streets in adjacent cities. This forms the basic intra- and inter-connected transportation system. A portion of gas tax collections goes into the State Aid fund, and is distributed to cities and counties using a complicated formula. to use the state aid funds, cities and counties must design to the state aid standards. This is supposed to assure some uniformity in design, so for example a street that is four lanes wide in one city doesn’t suddenly go down to two lanes when it crosses a city boundary.

    • Submitted by Bill Lindeke on 07/29/2014 - 02:35 pm.


      This is helpful clarification. I often have to trim articles to get them to a readable length and some of the specific detail gets squeezed out.

  4. Submitted by Adam Froehlig on 07/29/2014 - 08:28 pm.

    Complete Streets statute

    Bill, did you know about this?

  5. Submitted by mark wallek on 07/30/2014 - 09:45 am.

    making do

    Minneapolis should not be proud of the shoe-horned in bike lanes, their tendency to disappear, and the fact that the majority of bikers remain immature on the road this long after the lanes were put in. Almost every evening in the Como area by campus one can witness this lack of maturity. And when was it legal to ride with no illumination at night? The former mayor what’s his name did the city a disservice rushing this system into place and telling police not to ticket bikers. There should at least be ticketing for these immature behaviors, not to mention licensing and maybe insurance as well. How else will they mature without consequences? I know the person knocked down by a biker who’d love to have his expense compensated.

    • Submitted by Chris Farmer-Lies on 07/30/2014 - 01:48 pm.


      Meant to reply, not sure how my comment landed elsewhere.

      I already explained to you why licensing bikes is a terrible and completely nonsensical idea. Please review my comment to you here:

      • Submitted by Todd Hintz on 07/30/2014 - 04:34 pm.



        You made some good points there in your post about licensing. I’d like to add that licensing is generally correlated to the wear and tear a vehicle puts on the road. So a bus license is more expensive than a car license. And a license for a semi is more expensive than a bus.

        Using that standard, the license for a bike would be negligible as their impact on road maintenance is also negligible. Two hundred pounds for a person and their bike doesn’t have the same impact on a road as a 2200 pound person plus sedan, let alone a fully loaded semi. To put it in perspective, if you charge licensing fees based on the proportion of wear and tear a bike puts on a road compared to a car, you would at most charge the biker a couple of bucks. That would mean you’re creating a whole new government structure that loses money as it would cost more to administer the program than it would take in. Not to mention that, as Chris pointed out, a license would discourage people from riding bikes as it adds another barrier.

        An alternative would be to raise the cost of a bike license, but that would discourage even more people as well as have the double whammy of asking bike riders to subsidize drivers by paying more than their fair share. That’s hardly an equitable system.

        I can understand that some people are upset by the perceived free ride (pardon the pun) that bikers get, but a license is not the solution.

        • Submitted by mark wallek on 07/31/2014 - 12:31 am.


          my idea is that a license provides a means of reference, like a car license. So that the next time a bike hits the pedestrian I mentioned and knocks them down, there’s a visible number that ultimately references the owner. Or the next time a biker whizzes between two cars and there’s an accident consequentially between 3 cars, it’s possible that a visible number could support accountability if present. I’ve seen the first and experienced the second. I like the idea of bikes on the road, but I insist on responsibility and mature execution of movement because the same thing is expected from me.

          • Submitted by Matthew Steele on 08/01/2014 - 10:18 am.

            Mark, it sounds like you could use a little more bike riding in your life. It gets you places while reducing your stress about the world around you rather than increasing it like when you’re in a car.

  6. Submitted by Bill Lindeke on 07/30/2014 - 10:23 am.

    still have to deal with the variance project

    Yeah, I’d heard about this legislation. It helps, but I still don’t think it changes the basic dynamics of the situation. People still have to get variances, and the standards are still there influencing public works’ departments etc.

    Here’s the relevant part of the statute:

    Subd. 5. Variances from engineering standards.

    (a) When evaluating a request for a variance from the engineering standards for state-aid projects under chapter 162 in which the variance request is related to complete streets, the commissioner shall consider the latest edition of:

    (1) A Policy on Geometric Design of Highways and Streets, from the American Association of State Highway and Transportation Officials; and

    (2) for projects in urban areas, the Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities, from the Institute of Transportation Engineers.

    (b) If the commissioner denies a variance request related to complete streets, the commissioner shall provide written reasons for the denial to the political subdivision that submitted the request.

  7. Submitted by Chris Farmer-Lies on 07/30/2014 - 11:39 am.

    I already explained to you why licensing bikes is a terrible and completely nonsensical idea. Please review my comment to you here:

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