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Roundabouts are here to stay — and for good reasons

MinnPost photo by Judy Keen
Roundabouts originated in Great Britain and over the past decade have become increasingly popular across the United States.

Love ’em or loathe ’em, roundabouts are here to stay.

The alternatives to standard intersections controlled by stop signs or lights slow traffic as it flows in one direction around a central island to several exits.

There are about 120 in use on state, county and local roads around Minnesota, says Jim Rosenow, design flexibility engineer for the Minnesota Department of Transportation, and about 30 more are being built or are in the design phase.

He likes roundabouts and thinks Minnesota drivers are getting accustomed to them. “Now that I know how much less delay is involved with roundabouts compared with signals,” Rosenow says, “I have a hard time sitting at a signal waiting for a colored light to tell me what to do.

“In a roundabout, if you can go, you go. They’re very simple and efficient.”

Rosenow notes that safety also is enhanced at roundabouts because there are no red lights for vehicles to run and because reduced speeds reduce the odds that pedestrians struck by cars are fatally injured.

“Roundabouts have emerged as a holy grail of sorts: an intersection form that processes a lot of traffic and improves safety.”

Roundabouts originated in Great Britain and over the past decade have become increasingly popular across the United States. Traffic engineers consider them safer and more efficient than standard intersections and better for the environment because they require less idling at stop signs or lights.

The Insurance Institute for Highway Safety says studies of intersections converted from traffic signals or stop signs to roundabouts found reductions of up to 80 percent in injury crashes and 35-47 percent decreases in all crashes.

Clear safety benefits

Rosenow says MnDOT is conducting a comprehensive study that will compare safety before and after roundabout construction, but the safety benefits already are clear.

In cases where roundabouts have replaced intersections with persistent fatal crashes, “in nearly every instance, the roundabouts have been successful in eliminating the fatalities,” he says.

“One of the reasons we’ll continue to build more is that we know there are quite a few people walking around today who wouldn’t otherwise be if it hadn’t been for roundabouts, and that’s a good feeling,” Rosenow says.

How to drive on roundabouts“They do work,” says Washington County traffic engineer Joe Gustafson. “Obviously opinions on them are varied among drivers, but they have been shown to be very good at reducing delay and also preventing fatal and injury crashes.”

Studies in Washington County found that afternoon rush-hour drivers made it through roundabouts in 58 percent less time than drivers on roads with similar traffic volumes that control intersections with signal lights, Gustafson says.

The Woodbury area has about 10 roundabouts and plans for more, says Klayton Eckles, the city’s engineering and public works director.

“They’re an excellent alternative to a four-way stop sign,” he says. “If you put them in the right location, where somebody was going to have to stop anyway or likely stop, you reduce travel time, driver frustration and fuel consumption.”

Roundabouts can be a little intimidating for drivers encountering them for the first time, Eckles says, particularly on more complex versions where two four-lane roads intersect, requiring more than one lane circling the center island.

Because of a rash of minor fender-benders, Woodbury’s busiest roundabout, at Radio Drive and Bailey Road, was recently modified. Now the road with lower traffic volume enters and exits the roundabout in single lanes. “That cuts conflict points in half,” Eckles says.

Some problems

Drivers who don’t obey signs instructing them to yield to traffic already in the roundabout can cause problems, Eckles says. Another problem: Drivers who don’t get in the proper lane before entering the roundabout.

Roundabouts work best at intersections where the volume of traffic on both roadways is comparable, Rosenow says, and are less effective in hilly locations and at places where traffic tends to back up, such as near railroad crossings.

Rosenow says Minnesota’s first modern roundabout was build at the intersection of Frost Avenue and English Street in Maplewood. It opened in October 2002. The first one on MnDOT’s system, at the Medford interchange off Interstate 35 South, opened a month later.

The latter roundabout saved more than $500,000 in construction costs compared with traffic signals, Rosenow says, but in general roundabout construction is comparable to the price of signalized intersections.

A roundabout at the intersection of Radio Drive and Bailey Road in Woodbury.MinnPost photo by Judy KeenA roundabout at the intersection of Radio Drive and Bailey Road in Woodbury.

Some communities resist roundabouts. A few years ago, Forest Lake residents objected to a roundabout proposal. Last month, the San Marcos, Texas, City Council scrapped plans for a roundabout in response to citizens’ complaints. Commissioners in Benton County, Ore., could decide this week whether to proceed with a controversial roundabout proposal.

Gustafson says it’s more difficult to persuade drivers of the benefits of roundabouts if they’ve never driven them, but most drivers end up liking them.

That’s what happened with Pam Callaway. She moved to the Woodbury area a couple months ago from St. Louis and says that, at first, driving through roundabouts “freaked me out.”

“I was never quite sure when it was safe for me dive in there,” she says. “Finally I figured out that everybody in the roundabout is driving pretty slowly, so when there’s an opening it’s usually safe to enter.”

Now that she’s accustomed to them, she’s a fan – except for one gripe.

“I feel like I’m spending less time sitting at red lights, which is good,” Callaway says. “But I get frustrated with other drivers who haven’t learned yet how to navigate them. They tend to sit forever waiting for all cars in the roundabout to disappear before they dare to enter. Drives me nuts.”

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Comments (38)

  1. Submitted by Nick Wood on 11/05/2013 - 11:02 am.

    urban environments?

    I wonder if roundabouts can be used for busy urban intersections where space is limited — say the intersection at Snelling and University Avenues in St. Paul?

    • Submitted by Scott Batson on 11/05/2013 - 12:25 pm.

      roundabout space

      Single-lane modern roundabouts (90-120 feet in diameter) can handle intersections that serve about 20,000 vehicles per day. Two-lane modern roundabouts (150-220 feet in diameter) can serve about 50,000 vehicles per day. Right-turn slip lanes can increase that number if needed (just like for signal intersections). Is that light rail going in? It doesn’t look like there is enough space, presuming you need all those lanes. Light rail is not such a problem. Salt Lake City has light rail running through a modern roundabout, as do several in Australia.

      • Submitted by michael tobin on 02/23/2015 - 04:11 pm.

        handling traffic

        We have a roundabout in Forest Lake, MN. hwy61 and Broadway. It was an expensive replacement for a perfectly good, working stoplight in a low speed intersection(30 mph). Hwy 61 is a four lane north and south, Broadway is a four lane east and west. It does NOT work well at all and is more dangerous and is difficult to navigate. It causes great traffic jams at busy times. Sometimes blocks long. Even a stop sign would be better. My dentist office overlooks that intersection and I have witnessed accidents while I was there. The people who work there tell me there have been more accidents there since it was completed a few years ago, than there ever were before it was installed. A lot of people take side streets to avoid it. It was originally two lanes all the way around and did not work well, so it was reduced at the intersection(with pavement marking) to one lane all the way around and now it is worse. I don’t buy into the idea that they only improve safety. Not a fan. That was a ridiculous waste of tax dollars and it’s not over yet. Who will pay to change the underlying infrastructure to put a stoplight back? It will never happen. Someone would have to say it was a mistake. As for snow plowing being easy, let’s hear a response from a plow driver with a tandem truck.

    • Submitted by Mike Worcester on 11/05/2013 - 01:53 pm.

      Possibly

      They could since the Roundabouts you see in rural areas (there are two on State 7 just west of Minnetresta) were made to accommodate truck traffic. The one seen in the pic accompanying this article has that apron for truck trailers. In urban areas where you see less of that type of vehicle usage, they could, but one impediment could be how those intersections are currently laid out and removing parts of someone’s front yard or business parking lot to make room.

    • Submitted by Jeff Klein on 11/05/2013 - 02:47 pm.

      Good when there’s space

      It seems like they are too wasteful space-wise for most urban environments, but they are nice in the suburbs. There is a series of three on old MN-95 south of I-94 through and they really seems to calm the traffic. I wonder if that might lead to a little more business along that stretch.

      • Submitted by Scott Batson on 11/05/2013 - 05:04 pm.

        Intersection Space

        Modern roundabouts need more space right at the intersection, for the smooth, low-speed flow of traffic. Signals need more space to store parked cars – the ones waiting their turn to go through or make left turns. Depending on the amount of traffic, it could be the roundabout that impacts fewer properties, though it might be more intense.

  2. Submitted by Sheldon Mains on 11/05/2013 - 11:29 am.

    pedestrians, bikes and roundabouts

    This article says nothing about pedestrian and bike safety. It doesn’t even mention in the side bar that cars are required to yield to pedestrians in crosswalks at roundabouts.
    With the fact that Minnesota drivers rarely yield to pedestrians (even though it is a the law), that cars tend to be going faster with roundabouts, and that cars tend to not look for bikes, roundabouts are potential disasters for non-motrized traffic (bikes and pads). I wonder if the author has every tried to ride a bike through one of the roundabouts or cross the intersection at a roundabout?

    “Now that I know how much less delay is involved with roundabouts compared with signals,” Rosenow says, “I have a hard time sitting at a signal waiting for a colored light to tell me what to do.” That just tells me that we find saving drivers a couple minutes is more important to traffic engineers than the safety of vulnerable road users. A “fender-bender” between two cars can mean death to a pedestrian or bicyclist.

    • Submitted by Scott Batson on 11/05/2013 - 12:27 pm.

      Pedestrians/Bikes and Roundabouts

      The best modern roundabout design for cyclists provides two choices. The more confident cyclist should merge with through traffic and circulate like a motorist. This is made easier by the low-speed operational environment of the modern roundabout.
      http://vimeo.com/54317041 and http://vimeo.com/61988764
      The less confident cyclist should be provided a ramp to exit the street and use a shared use path around the roundabout. Such paths are at least ten feet wide and cyclist should operate a low speeds, crossing at the pedestrian crossings. http://tinyurl.com/roundabouts-and-bikes
      Sometimes space constraints, as with other intersection types, limit ideal design.
      All modern roundabouts have median islands separating incoming and outgoing auto traffic. Pedestrians don’t have to find a gap in two directions of traffic, just one. This is safer for pedestrians, especially for younger or older ones, because they only concentrate on one direction of traffic at a time. This is what is meant by two-phase. Cross the first half, pause if you need to, then cross the second half. On multi-lane crossings pedestrian beacons or signals are often added if the auto (or pedestrian) traffic is too numerous. The signals are also two phase, usually requiring the pedestrian to push a second button when they get to the median. The median can also have a Z path to reorient the pedestrian to view oncoming traffic. Also, the signals usually rest in off, so they are only activated if a pedestrian needs the help crossing. This way only motorists that need to stop are delayed.

      • Submitted by Sheldon Mains on 11/05/2013 - 03:39 pm.

        “find a gap in the traffic”

        Minnesota law requires cars to stop for pedestrians in crosswalks –even unmarked ones. Your comment about “Pedestrians don’t have to find a gap in two directions of traffic, just one.” points to the reality of roundabouts– The pedestrians are relegated to 2nd class road users that have to wait for the cars! This also is the problem for bikes using the side paths–and compounding that problem is MN law–cars don’t have to yield to bike riders in crosswalks–you have to get off your bike and walk to have right-of-way (that is something every bike commuter wants to do all the time!)–if the cars will even give you the right-of-way that state law requires!

        If it is two lanes going the same direction, the pedestrian or cyclist has a double threat–the car in the first lane may stop and the car in the second doesn’t–like some bad accidents on 28th street and the Greenway in MPLS (because of those, that is now narrowed to one lane in each direction.)

        Regarding two-phase signals: wow, having to wait for two signals to cross one street. That is SO pedestrian friendly!

        Roads and intersections MUST be designed for all users–not just cars. Bikes and pedestrians have the right to safe and convenient infrastructure as much as car drivers.

        • Submitted by Pat Berg on 11/05/2013 - 04:47 pm.

          If you click on his name . . . .

          You’ll see that Scott Batson hails from Woodland, Washington – so one might be understanding if he lacks familiarity with Minnesota traffic laws.

          On the other hand, his icon is a traffic sign and that – combined with his writing style – leads me to suspect he is some form of traffic engineer or some such that is defending a form of traffic management he has perhaps had some involvement in the design and installation of. That being said, he probably should make it a habit to check on the local traffic laws when choosing to comment/defend a traffic management scheme in an area other than that where he lives.

          And my experience with two lane roundabouts is that I had better REALLY watch the cars to my right when I am planning my legal exit from the inner lane of the roundabout. Once I was almost clipped by a driver who was NOT exiting, and once by a driver who was diving into the roundabout thinking I was still going around rather than making my legal egress. I drive through this particular roundabout on a fairly regular basis, and after the two incidents described, I double-checked to be darn sure I was not the one in the wrong. I wasn’t.

          These stupid things are accidents waiting to happen!

          • Submitted by Scott Batson on 11/05/2013 - 05:07 pm.

            Great sleuthing, so what?

            Your ignorance that traffic laws throughout the US are based on the UVC is understandable. The minutae of traffic law and engineering can be quite boring. All patronizing aside, visit the web links I’ve provided, or do your own web searches, if you don’t know much about modern roundabouts.

            • Submitted by Pat Berg on 11/05/2013 - 06:54 pm.

              What for?

              How would researching the UVC (yes – I Googled it, and you can’t read it if you’re not a member of the National Committee on Uniform Traffic Laws and Ordinances) change the fact that I almost got clipped twice even though I was following the lane markings properly?

              Minutae won’t save me at moments like that. A bad design is a bad design no matter how many engineers sat around a table outshouting one another to put it together.

          • Submitted by David Greene on 11/06/2013 - 09:52 am.

            Exiting

            Did you signal your exit? If not, the driver entering *should* assume you are continuing in the roundabout.

            • Submitted by Pat Berg on 11/06/2013 - 03:41 pm.

              I was going straight

              You’re supposed to signal if you’re turning right or left. Except for the “bobble” around the central island, I was going straight. No need to signal in any of the articles I’ve read on multilane roundabouts.

              The time I almost got clipped from the person continuing, they were in the righthand lane and were supposed to have either turned right or continued straight alongside me. Instead, they incorrectly continued around which is how I almost got clipped.

              The other time, it was a person entering who assumed I was continuing around instead of going straight (plus “bobble”) and dived in as I was exiting – just missing me. They were also in the wrong as they are supposed to wait for traffic to clear before entering.

              • Submitted by Pat Berg on 11/06/2013 - 06:35 pm.

                Minnesota Statute 169.19 TURNING, STARTING, AND SIGNALING

                Subdivision 1.Turning at intersection

                Subd. 5.Signal to turn.
                A signal of intention to turn right or left shall be given continuously during not less than the last 100 feet traveled by the vehicle before turning. A person whose vehicle is exiting a roundabout is exempt from this subdivision.

                • Submitted by Allan Holmstadt on 11/08/2013 - 01:13 pm.

                  Maybe so, but that doesn’t mean you shouldn’t

                  While you aren’t required to signal, it’s never a bad idea to make it clear what your intention is. Is being right more important to you than minimizing the chance of an accident?

        • Submitted by Scott Batson on 11/05/2013 - 05:01 pm.

          Read it again

          It would be nice if you read the whole post before commenting. I discussed how to handle double threat.
          Modern roundabouts operate at around 20 mph. Most motorists going this slow readily yield to pedestrians waiting to cross. If you’ve not experienced it, it may be hard to believe. If you looked up pedestrian crashes in your city, you’d find most of them happening at signalized crossings. Einstein is attributed with saying, “Doing the same thing over and over and expecting different results is one definition of ….” look it up.

          • Submitted by Charles Holtman on 11/05/2013 - 05:15 pm.

            bicycles & pedestrians

            As a driver I’m a big fan of roundabouts (note: they’ve been used in S New Jersey for at least the past 50 years) but even as an experienced & pretty fearless bicyclist I don’t like riding through them if there’s much traffic – mostly because there are too many stimuli for the motorist in too many directions for me to trust that I will be seen. Further, I would suggest that pedestrian/bike crossings adjacent to roundabouts (i.e., across the roads entering and emerging from the roundabout) need to be set at a distance from the roundabout sufficient for a motorist to exit the roundabout, turn his/her attention to the road ahead, and slow or stop for the crossing bicyclist or pedestrian. One roundabout that does not meet this standard is the one near Minnehaha Falls, and I think it is dangerous. The detour this requires for a pedestrian may be disadvantageous in a very urban setting but isn’t an issue otherwise.

            • Submitted by Todd Hintz on 11/05/2013 - 10:23 pm.

              Minnehaha Roundabout

              I frequently go through the Minnehaha roundabout, both as a driver and as a biker. I can’t say as how I’ve had an issue in either mode of transportation, then though the area gets heavy bike and car traffic.

            • Submitted by Scott Batson on 11/06/2013 - 12:31 pm.

              Know your circular intersectioins

              Many people confuse older styles of circular intersections with modern roundabouts. East coast rotaries, large multi-lane traffic circles (Arc D’Triumph), and neighborhood traffic circles are not modern roundabouts. If you want to see the difference between a traffic circle, a rotary (UK roundabout) and a modern roundabout (UK continental roundabout), go to http://tinyurl.com/kstate-RAB to see pictures. And here’s another site that shows the difference between an older rotary and a modern roundabout: http://tinyurl.com/bzf7qmg
              The FHWA (http://tinyurl.com/fhwaRAB) has a video about modern roundabouts that is mostly accurate (http://www.youtube.com/watch?v=uhHzly_6lWM ).

    • Submitted by Phillip Pyram on 11/05/2013 - 08:35 pm.

      Ped Safety

      MnDOT actually commissioned a study on ped safety and vehicle/ped interactions at roundabouts – probably the most thorough and innovative of its sort in the nation thus far. The findings are that, due largely to the slow vehicular speeds at the roundabout entries and exits, peds are safer than at conventional intersections. The other secret is that you actually HAVE vehicular/ped interactions at roundabouts rather than the “trust the lights” method that too often gets peds run over at traffic signals. The bottom line is that a ped struck by a vehicle traveling 40 mph has an 85% chance of dying; at a 30 mph vehicular speed, their chance is 45%; and at 20 mph, the chance of a fatality is 15%. The difference between roundabout speed and green-light speed is generally the difference between life and death.

  3. Submitted by Mike Downing on 11/05/2013 - 11:57 am.

    Roundabout support from both conservatives and liberals.

    Conservatives and liberals should both support roundabouts. Fiscal conservatives should like roundabouts since they waste less gasoline, electricity, save time and are safer. Liberals should like roundabouts since they reduce emissions including CO2, less expensive for the poor, less maintenance costs that can be applied to social welfare and are safer.

    Roundabouts are truly “Win/Win”!

  4. Submitted by jason myron on 11/05/2013 - 01:20 pm.

    My only issue

    is with clueless drivers who treat the yield sign at the entrance of the roundabout as merely a suggestion.

  5. Submitted by David Frenkel on 11/05/2013 - 02:02 pm.

    MNDOT should get an award for stuffing as many roundabouts and freeway exits in one place as they did at the intersection of Highway 169 and I-494. The multiple configurations, lane changes, exits are poorly marked and confusing.

  6. Submitted by Pat Berg on 11/05/2013 - 07:03 pm.

    So with tonight’s forecast . . . . . .

    How well do the snowplows do navigating these roundabouts? (I haven’t yet dealt with them much in the wintertime, but I’m about to.)

    • Submitted by Scott Batson on 11/06/2013 - 12:33 pm.

      Snow Plows

      Most plow operators know how to drive in a circle. Video of snow plow: http://tinyurl.com/rab-snowplow

      • Submitted by Pat Berg on 11/06/2013 - 03:28 pm.

        What’s with all the video links?

        I’m not going to sit here watching videos.

        Yes, I know snowplow drivers can drive in a circle.

        But lots of plows are pretty big, and I wondered how well they navigate the turning radius of the roundabouts I’ve seen.

        Also, some of the roundabouts have fairly intricate pavement markings as well as separated entrance and exit lanes (moreso on the multilane ones I’ve experienced). If the plows can’t navigate through all of that as well as successfully clear enough snow away to get full road width and expose the pavement markings, it could create some basic winter to summer changes in the way any given roundabout is able to function.

        It was just something that occurred to me as a person who has a lot of experience with the less-than-complete snow removal that goes on around here as a result of tight governmental budgets.

        • Submitted by Phillip Pyram on 11/07/2013 - 12:52 pm.

          The plows can navigate the roundabout radii just fine. In some ways it’s easier and quicker to clear a roundabout than a conventional intersection. The more difficult aspects involve the intricate geometry on the outside of the circulatory roadway – it’s tough to know where all the curbs are when they’re covered in snow.

          • Submitted by Pat Berg on 11/07/2013 - 01:40 pm.

            Yup – the curbs

            I was wondering about the curbs, too. Forgot to ask about them.

            This morning I was remembering that super-snowy day we had early in the season last year. You couldn’t see the edges of the road – I drove in to work (very carefully!) literally going on “landmarks” to confirm that I was continuing generally down the middle of the street. No idea which lane I was in, but on a morning like that, you just kept going in a straight line and hoped you could keep from hitting the curb on one side or the other.

            If I’d had a roundabout on my route (particularly a double-lane one with all those extra little islands splitting out the lanes and such) things would have become quite a bit more challenging in terms of “avoiding the curb”. Wonder how many of them got major abuse from plow blades trying to figure out exactly where things started and stopped?

            • Submitted by Phillip Pyram on 11/08/2013 - 09:15 am.

              There is nothing new here. There are plenty of channelizing islands that must be dealt with – such as when the right turns are channelized with triangular islands at conventional intersections. Nothing is easy when it’s snowing hard.

  7. Submitted by Jean Garbarini on 11/05/2013 - 07:27 pm.

    Not pedestrian or bicycle friendly

    These might work in the ‘burbs, but they are incredibly inconvenient and dangerous in urban areas for peds and bikes. Minnehaha’s Godfrey Parkway is a perfect example of this.

    • Submitted by Scott Batson on 11/06/2013 - 12:36 pm.

      Maybe it’s the motorists?

      Safety is a combination of things. Have you requested enforcement of the traffic laws at your problem locations? Most states require motorists to yield to pedestrians at crossings, marked or not, and some states require motorists to fully stop.

    • Submitted by Theo Kozel on 11/12/2013 - 02:27 pm.

      Perplexing

      I live 3 blocks from the Godfrey Parkway roundabout and am utterly perplexed as to how anyone could consider it a bad example. I navigate my way through it by car, bicycle, and foot (with two large, impatient dogs to boot) literally hundreds of times a year and vastly prefer it to the other intersections I have to traverse. It can be quite busy but it works supremely well from my experience with it.

  8. Submitted by Maureen Cannon on 11/09/2013 - 03:37 pm.

    Roundabouts

    I think roundabouts are great, so efficient. Now, if MNDot would get busy and design them for the exchanges where the driver exits onto an intersecting road, hiway, etc. Get rid of the cloverleafs! They use roundabouts in Europe and they work. Let’s get with it.

  9. Submitted by Paul Udstrand on 11/12/2013 - 10:17 am.

    This and that

    First, my biggest complaint about Roundabouts is drivers who stop or slow down unnecessarily, the whole point is to keep moving, there are not stop signs for a reason.

    Second, I think the actual first real Roundabout in MN was over on the Minnehaha Parkway by the falls. No one ever talks about but I’m pretty sure it was installed before 2002 as part of the re-route.

  10. Submitted by Paul Udstrand on 11/12/2013 - 10:48 am.

    This and that

    First, my biggest complaint about Roundabouts is drivers who stop or slow down unnecessarily, the whole point is to keep moving, there are not stop signs for a reason.

    Second, I think the actual first real Roundabout in MN was over on the Minnehaha Parkway by the falls. No one ever talks about it but I’m pretty sure it was installed before 2002 as part of the Hiawatha re-route plan.

    Actually, it’s not true that no one talks about the parkway roundabout, it was listed as one of the worse bike intersections by City Pages a few while back. It’s not, just use the bike path instead of pretending your a car and it’s perfectly safe and easy to navigate. Those bike “drivers” along the parkway are a real pain.

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