What if Hennepin Ave Had a Roundabout?

I was waiting for the number 6 bus at Hennepin Ave and S 1st St, near where I live, and I was watching the vehicle traffic. I noticed that the semaphore intersection was not very efficient at handling left turn vehicles. There was a part of the cycle when left turns in both directions on Hennepin Ave would go, and I saw a trickle of 2-5 cars make their turns as traffic backed up in all directions. There also was the flashing yellow arrow left turn, which worked like a regular green light, having left turners yield to oncoming traffic. The time was just before 5:00 PM, so there was heavy traffic in both directions.

Hennepin Ave Roundabout Google Earth

April 28, 2018 satellite photo with 95-foot radius circle in yellow.

Taking this in, I wondered if it would be possible to build a roundabout at the intersection. After my evening meeting, I opened Google Earth and saw the radius of a circle that one could draw. This happened to be about 95 feet.

According to the Federal Highway Administration (FHWA), a roundabout of 95 feet would have vehicle traffic travel at about 20 mph (page 55 of PDF). This is not the speed some cars go right now, but it seems to me like a reasonable speed to make the space safer and reduce accidents.

With these facts in mind, I started to design in Adobe Illustrator a simple roundabout with a couple of unique features. I was influenced by a 2017 Vox feature on “shared space” traffic intersections in Britain. I decided to draw up a hybrid of a shared space — where there are no traffic lights and cars, bikes, and pedestrians share the road — and a standard FHWA roundabout where pedestrians cross a single right-of-way (street) like a traditional intersection.

Hennepin And 1st Street Roundabout Design

This roundabout design makes crossing far safer for pedestrians.

The first thing to note about this design is that it reduces lanes. Left-turn and right-turn lanes are eliminated in return for more space for pedestrians.

The second note is that I designed the roundabout with 10-foot lanes. This is likely narrower than the current lanes, but would reduce vehicle speeds approaching the roundabout. However, there does appear to be space for a 20-foot, or two-lane, roundabout, and that is what is drawn here.

Benefits of a roundabout design

As a daily pedestrian, I appreciate traffic design that reduces the chance I may get run over by a postal semi when I run to grab a cup of coffee. Right now, there are many left turns from S 1st St that can be problematic for pedestrians crossing Hennepin Ave. The left-turn drivers are focused on avoiding a head-on collision and yielding to pedestrians is a secondary priority.

This design eliminates those issues. First, pedestrians only cross up to two lanes of vehicle right-of-way. Second, the traffic has a stop signal, and remaining traffic in the circle is coming from only one direction. In the current setup, pedestrians contend with right turns from drivers facing the other way and aforementioned left turns.

The vehicle signals would be either red arrow (stop, no right turn) or flashing yellow arrow (yield to other traffic).

Another feature of this design are bus lanes on both Hennepin Ave and 1st St. Buses park on 1st St as it is, and creating more space for buses will improve transit on-time performance and reduce bunching. Before writing this, I saw three 2C buses bumper-to-bumper on 4th St SE.

Close Up Of Hennepin Ave Roundabout Design

The design also features wide crossing areas, helpful when there are blocking vehicles.

One question that a planner would need to address is how much time should be allocated to the pedestrian portion of the signal. The FHWA recommends designing for a walking speed of 3.5 feet per second. The question is whether to time for crossing one street or going across the diameter. Going across the diameter of the roundabout design would be about 54 seconds. If there was public art or other barriers in the middle, the time could be up to 85 seconds. Of course, there could be a short time of say 30 seconds and pedestrians would have to wait a cycle before completing their trip across both Hennepin Ave and 1st St.

I am not a public works planner or engineer, but I am a pedestrian, a transit rider, and a driver on occasion. It saves lives and improves livability to have streets that don’t work like highways with switches. Putting a roundabout on Hennepin may be radical, but so were a lot of things we take for granted now.

Do you cross streets or speed through them? What do you value as a pedestrian? What public art would you put in the middle of Hennepin? Share your stories and insights in the comments.

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17 Responses to What if Hennepin Ave Had a Roundabout?

  1. Bill Lindeke
    Bill Lindeke April 25, 2019 at 2:28 pm #

    Cool idea. is this the best spot for it? or somewhere like Washington Avenue instead?

    • Mark April 26, 2019 at 10:17 am #

      Washington & Hennepin would make the most sense. It has higher traffic, especially with pedestrians. My biggest concern with a roundabout on 1st & Hennepin would be semi traffic coming out of the post office and if those large vehicles would be positioned properly to go through a roundabout especially with Conrad’s proposed street width reduction. By design they swing wide, and the last thing we want is an increase in accidents or pedestrians on the islands being clipped by a wide turning vehicles.

      Also to clarify the bunching of buses, the biggest culprit right now is the Marquette layover between 1st Street & Washington. Numerous buses are stopping for extended periods of time, and even blocking other buses from using the left lane to move ahead. This is causing stacking issues back onto 1st Street all the way in front of the post office.

  2. Sean Hayford Oleary
    Sean Hayford Oleary April 25, 2019 at 2:38 pm #

    I’d love to see (a lot) more roundabouts in Minneapolis, but downtown seems like a bit trickier of an area to do it.

    Most of Minneapolis doesn’t require full traffic control on every single block — so signals are only every few blocks or farther apart. Downtown is signalized at almost every corner, and the signals work together in a good, coordinated system.

    The intersection you suggest is good in that it’s on the edge of the grid, but I’m not sure it’d have enough traffic to balance Hennepin. Not sure.

    Can you explain a bit more about the signalization you want to see? A typical modern roundabout has no signals, although some new ones have included pedestrian flashers.

    Franklin is a corridor near downtown without that downtown signal system that I think would be a terrific place for adding roundabouts. (Specifically like at 3rd, Nicollet, and Lyndale)

    • Conrad Zbikowski
      Conrad Zbikowski April 25, 2019 at 4:10 pm #

      The traditional FHWA intersection has pedestrian crossings across the four streets at the intersection with the roundabout, with vehicles (hopefully) yielding to pedestrians in two-way traffic.

      My approach would have a stop signal for vehicles entering the roundabout. After a certain lag time, the cross signal for pedestrians to cross the one-way roundabout would start. The benefits are that pedestrians cross only a one-way and the crossing is shorter. This approach assumes that vehicles are able to clear out of the roundabout or be stopped during the pedestrian crossing time. In heavy traffic, this might not be the case. So that’s a downside.

  3. jack April 25, 2019 at 3:28 pm #

    I like the idea of a roundabout downtown, anchored with a great sculpture, statue or fountain in the center. Maybe a commemorative arch?

  4. Janne Flisrand April 25, 2019 at 3:39 pm #

    MPR did a story on the most dangerous intersections in Minneapolis for people on bikes (which are also generally the most dangerous for those walking and rolling), and this makes the list. Here’s the story. It needs something for safety, something that hasn’t happened in the five years since the report and story came out.

    (I was part of it, they strapped cameras to my bike to show what it feels like riding through the intersections, as it happened that day, in the snow.)

    https://www.mprnews.org/story/2014/05/07/bicycle-safety-minneapolis

  5. Eric Anondson
    Eric Anondson April 25, 2019 at 6:50 pm #

    The biggest cause of congestion downtown is waiting at stop lights. I believe if downtown was mostly roundabouts we could drop to 2 lanes throughout the central business district. How to handle the at-grade LRT intersections though will still be a challenge.

  6. Monte Castleman April 25, 2019 at 6:51 pm #

    You likely would treat this like a crossing with a refuge island available, where the overall walk time is somewhat shorter than 3.5 feet/s second across the entire intersection, but long enough that most people walking normal speed would be able to make it across.

  7. Isaac Warner April 26, 2019 at 2:02 pm #

    I would love to have seen a traffic circle incorporated into the Hennepin/Lyndale mess near Loring. Missed opportunity, imo.

  8. Scott April 26, 2019 at 4:33 pm #

    This round-about concept comes up on streets.mn every so often. Are there any examples of truly pedestrian-friendly places where they have been built in MN? If so, where? If not, why? MN places I’ve seen them seem very car-focused/ suburban/ rural, not places someone wants to walk.

    Wish the City would get the U.S.P.S. to move the postage facility out of downtown so streets don’t have to be designed for their trucks, the building can get incorporated into a redevelopment, and that ugly ramp can be torn down.

    • Sean Hayford Oleary
      Sean Hayford Oleary April 26, 2019 at 5:04 pm #

      66th and Lyndale right now is a pretty good example. Lots of high density residential, medical office, and some quick service food. Not on Street View yet, since it was just finished this year. I just rode my bike through here 4x today.

      Minnehaha Ave and Godfrey Pkwy is also a pretty good example. I guess that’s pretty bucolic for an “urban” roundabout, but lots and lots of bicyclists and pedestrians close to the Falls.

      Edina’s 70th St roundabouts by the Galleria are also good examples of smaller scale roundabouts. One of them includes the terminus of their Southdale-area greenway, the Edina Promenade.

      • Scott Stocking April 27, 2019 at 7:54 pm #

        I’ve ridden through the Minnehaha/Godfrey intersection a number of times heading “west” on the bike path. I do not like the crossings at all, but that is probably because if you are on the trail and not on the street, you are forced to cross traffic at an intersection away from the roundabout itself. You are crossing the street to the right of the roundabout and the driver is looking to left to see what traffic is passing through or exiting the roundabout. Drivers are not looking to their right to see the bicycle traffic crossing the street.

        Sean, when you have been using the roundabout at Lyndale and 66th are you on the street and have you felt safer than when it was a regular t intersection?

        • Sean Hayford Oleary
          Sean Hayford Oleary April 29, 2019 at 9:10 am #

          I am surprised to hear that you are feeling drivers are only looking to the left. The Godfrey roundabout has crosswalks set extremely far back (as you note), so there’s really no reason to be looking only to the left at that point — you have a ways to travel, so you are unlikely to be able to make your (vehicular) decision that early.

          That’s not to say it doesn’t happen, but that is definitely a driver education issue that could be worked on. One nice thing about roundabouts is that you can make the crosswalk determination first, then wait on the far side of it and make only the vehicular yield determination.

          For my experience on 66th/Lyndale, there are a few things I like better about it than the old signal:

          Going east-west (the most common movement for me), I only have to cross one lane at a time. Before it was 5 lanes in a row
          Right-of-way is instantaneous now. Before you had to wait for a compatible green light.
          When bicycling on the roadway, there’s no awkward issue of would-be right turn on red cars waiting impatiently behind.
          There is no conflict with left- or right-turning cars in the same way. There is one type of possible conflict (crossing the crosswalk, straight on), and it’s a lot more controlled and predictable.

          The one thing I don’t like about it, unsurprisingly, is that there is a risk of cars simply not yielding. This is frustrating and can be frightening when it happens, but I don’t think it is any more common than failure-to-yield left or right turns at the old signal. It isn’t perfect, but I think it beats a signal.

        • Adam Miller
          Adam Miller April 29, 2019 at 10:13 am #

          I bike through the Minnehaha Godfrey roundabout all of the time (like 5-6 times a week, probably, some of those during morning rush). The good part is that there is sufficient volume of a people on bikes and walking on the adjacent trails, that drivers usually are paying close attention and many will yield to crossings (where maybe they aren’t even obligated to). With the crossings set back from the roundabout, I’ve generally thought it gives drivers the opportunity to switch their eyes from the left, while entering the circle, to the right, where they are existing. (Or if you’re going the other way, drivers have to deal with the crosswalk before they can start dealing with entering the circle.)

          Maybe that’s not the right way to do it (I don’t know), but here at least, it seems to work well.

  9. Adam Froehlig
    Adam Froehlig April 28, 2019 at 10:12 am #

    Four things I just noticed, especially since the author references FHWA design guidelines.

    First, 95 feet is below standard for a single-lane urban roundabout (minimum 100ft) and especially for a 2 lane roundabout (which is more likely what would be recommended).

    Second, lane width in the roundabout itself operates very differently than typical lane width on a street because of the curvature involved, especially if it’s a multilane roundabout. You typically need 14-16ft per lane, depending on the design vehicle.

    Third, because of the Post Office trucks, you would most likely need a truck apron on the inside circle.

    Lastly, and perhaps most importantly: roundabouts are NOT signalized. Once you throw a signal into the mix, it adds a whole different level of complexity, one that is better reserved for larger circles. Given the space constraints at Hennepin/1st, you’re no better off with a signalized circle than you are with a traditional 4-way signal.

    • Sean Hayford Oleary
      Sean Hayford Oleary April 29, 2019 at 9:16 am #

      I agree with these critiques. The one thing I’d add is the fact that there is an increasingly common mini-roundabout/compact roundabout style, with center island diameters of 45 to 80 ft.

      I do not think that design would be appropriate at this specific intersection — as Adam says, you’d likely need double lane. But I think it would be terrific for many of the medium-to-low volume signals on two-lane streets. Think 46th and Bloomington, 28th Ave and 42nd St, etc.

      It might also be a good way to preserve parking fairly close to the intersection. That’s been an issue where volume requires a left turn lane. (See 50th & Xerxes, where the lane configuration moves cars well but really sucks for the small businesses there)

    • Andrew Evans April 30, 2019 at 1:42 pm #

      I was looking around streets in France that I’ve driven for examples of signaled and non-signaled roundabouts. It seems like signals are used when there are more than 2 or 3 roads coming together. We were unfortunate enough one year to come out of the Rue Fontaine de la Ville into this cluster of a controlled roundabout – 2-6 Boulevard de Riquier, 06300 Nice, France. Usually though from what I can remember, they aren’t controlled and are mostly user friendly – although signed horribly, but that’s a French thing.

      It’s also worth noting that in French cities it’s still a ton of stop signs/lights. It’s not like they have roundabouts on every intersection.

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