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Round is Resilient!

  • 1.  Round is Resilient!

    Posted 05-28-2019 07:42 AM
    Edited by Tirza Austin 05-28-2019 07:42 AM
      |   view attached
    ​Modern roundabouts are the most resilient intersections every invented.  No power needed:  they operate the same after a major storm as before: normally, safely and efficiently.  Unlike storm-damaged signalized intersections there is no need to divert badly-needed emergency crews to repair the traffic signals, because there aren't any.  Unlike power-dependent signalized intersections, there is no need to divert badly needed police operate the intersection and no need to divert badly needed emergency crews to restore power to the intersection.

    For more details about Hurricane Michael and modern roundabouts, see the attached Round is Resilient! article from the Journal of the Florida Engineering Society.

    Ken Sides, PE, PTOE, CNU-a, LCI



  • 2.  RE: Round is Resilient!

    Posted 05-29-2019 10:47 AM
    Edited by Tirza Austin 05-29-2019 10:46 AM
    As the design engineer for several roundabouts in Florida (and 2 in Carmel, IN), I wholeheartedly agree with Ken. When placed in the right location, modern roundabouts are not only resilient after storms, they operate more efficiently for drivers than traffic signals every day. For every intersection upgrade we should evaluate constructing a roundabout.

    Fraser Howe P.E.,F.ASCE

  • 3.  RE: Round is Resilient!

    Posted 05-29-2019 11:48 AM
    Interesting thoughts, and statistics regarding the use of roundabouts.

    My observations are that roundabouts are only safe and efficient if the users know how to effectively drive them.  In Florida, we are blessed with 19 million residents (neighbors) and over 110 million visitors, some of whom have rarely seen a roundabout and many of them only partially aware of how to navigate from point A to point B.  With a tendency for some of our local drivers to drive aggressively, only compounds the problem.  The social effects on engineering should not be discounted.

    I am waiting on FDOT's roundabout experiment at US41 (3 lanes both ways) 35,000 AADT and 10th street (2 lanes each way east bound 7900 AADT), one lane each way west bound<1000 AADT) in Sarasota to be completed.  Two approaches include gentle downhill grades.    Should be a test of the concept.

    Douglas Mann P.E.,M.ASCE


  • 4.  RE: Round is Resilient!

    Posted 05-29-2019 12:54 PM
    Edited by Tirza Austin 05-29-2019 12:53 PM
    ​Thanks for sharing your observations, Douglas.  I hope others will also weigh in with what they have seen watching modern roundabouts operate. 

    Much is made of user inexperience potentially causing crashes at modern roundabout, but keep in mind user errors at conventional intersections result in 8,000 fatalities annually in the USA.  Conventional intersections are unforgiving and cruel to users who err. 

    By design, the two most lethal intersection crashes cannot happen at modern roundabouts:  T-bone crashes and near head-on crashes. 

    Speeds through well-designed modern roundabouts are typically <25 and <17 MPH at 2- and 1-lane modern roundabouts, respectively.  Essentially nobody dies at 17 MPH.   

    FHWA has been saying for almost 20 years that modern roundabouts reduce fatalities by "more than 90%".  Now a PennDOT study based on 17 years of data found modern roundabouts:
    • Reduce fatalities 100%
    • Reduce severe injuries 100%
    • Reduce minor injuries 95%
    As Billy Hattaway has stated, "We're engineers; we can't ignore the data".

    There is some loss of efficiency as some drivers new to modern roundabouts unnecessarily pause at the YIELD sign...but nobody dies at a result.  Keep in mind that signalized intersections lose efficiency during every clearance interval.  Modern roundabouts are typically about 30% more efficient than conventional intersections.  Late at night most motorists experience zero delay, and pedestrians typically experience very little delay at all hours. 

    I agree the FDOT modern roundabouts on US 41 will be extremely interesting to observe, especially the one at Gulfstream and the one at Fruitville Road.  Maybe we could go together to watch them operate when they are ready?   Meanwhile, you can watch the 40th Street roundabout corridor in Tampa which has a series of three 2-lane modern roundabouts.  Crashes are down 58%. 

    Ken Sides, PE, PTOE, CNU-a, LCI

  • 5.  RE: Round is Resilient!

    Posted 05-30-2019 12:52 PM
    Edited by Tirza Austin 05-30-2019 12:52 PM
    I agree with Douglas. While roundabouts are good engineering solutions for the many reasons previously posted, American drivers are not used to them and that is why they are resistant to roundabouts.  My opinion, based on many years of driving experience, is that roundabouts are fine in low traffic intensity applications. In high traffic situations where cars are zooming by in every direction they can be very daunting to drivers not used to them and even dangerous. 

    Two years ago I was on vacation in England where roundabouts are much preferred to traffic lights.  I thought I was getting the hang of them.  One morning in York, I got creamed by a city bus as I navigated a busy roundabout. The bus' fault, he hit me in the rear.  Car totaled and a £5000 bus window smashed. No one hurt thankfully. This experience has dampened my enthusiasm for roundabouts. 

    As Douglas says, until citizens, not engineers, engage their elected officials to begin replacing intersections with roundabouts, it's not going to happen. Regardless of how much good sense they make.

    Bevin Beaudet P.E.,M.ASCE
    Bevin A. Beaudet, P.E., LLC.
    West Palm Beach FL

  • 6.  RE: Round is Resilient!

    Posted 05-30-2019 02:10 PM
    Edited by Tirza Austin 05-30-2019 05:31 PM
    Bevin, I disagree that we should wait for citizens to ask for roundabouts, since many have no experience with them. I've been in practice long enough to remember driver resistance to 4-way stops and actuated signals. We transportation experts convinced local agencies to pilot them and collect data that showed they were effective at reducing severe crashes and improving intersection operation. We must take the lead at evaluating roundabouts for new intersections and major reconstruction. Florida DOT has embraced roundabouts as part of their Complete Streets initiative, and many local governments are following. They, and the USDOT, have good guidance for locations where a roundabout is contra-indicated and we can learn from existing intersections where there are deficiencies - and avoid them in new projects. As we build more modern roundabouts drivers will get used them and appreciate their benefits.

    Fraser Howe P.E.,F.ASCE

  • 7.  RE: Round is Resilient!

    Posted 05-31-2019 09:56 AM
    I applaud all of you engineers who have, and continue to apply your creativity to improving our transportation networks.  I'm a water/wastewater engineer, so my previous post was based on a personal, rather than professional perspective. I agree professionally with your technical assessments of roundabouts, and am proud of your efforts. 

    I have to admit that after reading that Florida DOT (my state) is planning pilot roundabouts in Sarasota, I had a good laugh. Florida has the oldest population in the US and Sarasota leads the statistic. Drivers in their 80's (or even 90's) are common. They usually drive about 10 miles under the speed limit and come to a full stop before turning right on residential streets without stop signs or any sign of traffic except frustrated drivers behind them. This is no exaggeration.  Could FDOT have picked a worse location to pilot roundabouts, lol. 

    Bevin Beaudet P.E.,M.ASCE
    Bevin A. Beaudet, P.E., LLC.
    West Palm Beach FL

  • 8.  RE: Round is Resilient!

    Posted 06-01-2019 04:13 PM
    I live in Tampa, FL which is a stone's throw from Sarasota. Since we own a small condo in Longboat Key, we go down to Sarasota quite often including the intersection that is the subject of this discussion. In my 20 plus years of experience in driving through this intersection, never have I come across a situation where I had to wait or slow down behind another car that is being driven. I have encountered many motorists that have a tendency to speed or not sure about their chosen lanes, but they hardly ever slow down to create a problem. Perhaps the demographics of Sarasota is different from West Palm Beach, but I think in this case, the FDOT has made the right decision in selecting a round about. Will there be some difficulty in the beginning in getting used to a new system? you bet. However, I applaud FDOT's decision making as supported by exhaustive traffic studies.

    Gautam Ghosh P.E.,M.ASCE
    Consulting Engineer
    Tampa FL. 33647
    (813) 283-8033

  • 9.  RE: Round is Resilient!

    Posted 06-02-2019 06:55 PM
    There are areas of Florida with lots of round-abouts like Tallahassee and Gainesville, and some master planned communities use them extensively. Where I live in central FL they have been implemented with an unusual amount of public push-back BEFORE they are built, then people really like them once they are in. Much safer than lights due to the lower speeds and nobody gets killed with someone running a red light (someone running a light almost killed my mom a couple of years ago). Much cheaper to build and maintain, and under certain traffic flow rates may be more efficient then signalized intersections, especially if they traffic flow rate changes throughout the day from one direction to another, they are like automatic pressure relief valves that need to adjusting. 

    I have been fortunate to travel around the world a bit, and they are extensively used everywhere else in the world I have been to. We spent two weeks driving around New Zealand, and outside of the bigger cities, almost no traffic lights at all. Driving through one on the left side of the road was a bit odd at first to say the least, but like everything else, you get used to them.

    Andrew Kester, PE

  • 10.  RE: Round is Resilient!

    Posted 05-29-2019 04:21 PM
    My Florida county has installed a bunch of roundabouts over the past few years. It took a while but most handle them smartly. I like the fact one does not have to stop, if the round is clear. But your point about the aftermath of disasters is great, 100% correct, unless some poor driver mucks up the roundabout with an accident. Thanks.

    Lawrence Lippert M.ASCE
    Vice President
    HG&LL Engineering Inc.
    Sarasota FL
    (941) 377-7722

  • 11.  RE: Round is Resilient!

    Posted 05-29-2019 04:53 PM
    Edited by Tirza Austin 05-29-2019 04:52 PM
    ​I agree roundabouts help make our communities safer.

    During one of my trips for work, I saw the community I was visiting had paid advertisements on TV to teach people how to safely use roundabouts. Educating others, including non-traffic engineers, on how to properly use roundabouts is an important measure for adding them to a community and helping the public understand why they may be better than traffic lights.

    Kenneth Mika, PE M.ASCE
    (920) 393-8484
    Green Bay, WI

  • 12.  RE: Round is Resilient!

    Posted 05-29-2019 11:46 PM
    Edited by Tirza Austin 05-29-2019 11:45 PM

    As one of the individuals presently experiencing the after effects of Hurricane Michael, I could not agree more with brother Ken.  Having worked in Traffic Engineering for several years, I am of the opinion that well designed roundabouts should be used instead of traffic signals.  Signals waste a lot of time, energy and money.  They cause catastrophic crashes when violated. Roundabouts eliminate these issues.  The cost associated with a well designed roundabout is possibly higher when compared to a signalized intersection, but in the long run they will save thousands of dollars and most likely lives. 

    The problem I have seen is the lack of commitment from engineering managers in a political position to construct roundabouts. These individuals are more interested in protecting their "positions" than providing safe and cost effective measures to the public.  Engineers have the responsibility to reach out to politicians to educate them on safer designs as private citizens, through ASCE, or public service.   If we don’t advocate for safety, no one will.

    Anyway, I have heard thousands of times...."We just want a red light!"  It makes you wonder how many of the operators of vehicles on the road today managed to get a driver's license. Perhaps in the future there will be more people who will stand up for what is right and less of those who are just trying to protect a job position.

    His obedient servant,

    Harold "Mac" Watters, PE/PSC, Life M.ASCE
    Professional Engineer, Land Surveyor and Cartographer
    Panama City, Florida

  • 13.  RE: Round is Resilient!

    Posted 05-30-2019 10:57 AM
    ASCE offers several online courses on roundabout design, and how to identify & correct deficiencies in existing roundabouts. I have teken a couple for PDH credits and recommend them to my fellow engineers.

    Fraser Howe P.E.,F.ASCE

  • 14.  RE: Round is Resilient!

    Posted 06-09-2021 03:16 PM
    Edited by Tirza Austin 06-09-2021 03:15 PM
    Thanks everyone who weighed in with your comments.  I was disappointed to see engineers repeating some tired canards, such as 
    • People don't know how to drive modern roundabouts.
    • Old people can't handle them.
    Anyhow, two years have passed and now the modern roundabout at US 41 and Fruitville Road near downtown Sarasota is up and running.  You can go drive, walk, bike and skate it yourself.  A fantastic vantage point is the 8th floor Embassy Suites balcony on the SE corner--take your video and still cams with the widest-angle lenses you've got.  More details in this recent article in Roads and Bridges magazine: 

    A look at successful roundabout projects in Sarasota, Florida

    This is a serious modern roundabout moving a lot of traffic.  Interesting features include HAWKs at ped Xings and special striping with RPMs to delineate circulating lanes.  Please post here what you think after you've experienced it directly for yourself. 

    Ken Sides, PE, PTOE, CNU-a, LCI, RLRM
    Sam Schwartz Engineering
    Chair, ITE Roundabout Committee

    Ken Sides PE, PTOE, CNU-a, LCI
    Sr Transportation Engineer
    Sam Schwartz Engineering
    Tampa, Florida

  • 15.  RE: Round is Resilient!

    Posted 06-14-2021 03:19 PM
    Excellent article with clear diagrams, thank you! We drove roundabouts in Australia twenty years ago and they flowed smoothly even in multi-lane, heavily used areas. I was surprised on returning to the US to find that that the tendency here is to add stop signs and yield signs to roundabouts in an effort to control how people use them.
    I have not designed a roadway in decades, but have read that in the absence of signage, people make sensible decisions and are mindful of other drivers - those were pre-pandemic observations which seem to hold true for the emergency activation referenced in this article. Not sure why they have not been embraced more fully in the US.

    Patricia Eisenberg P.E., M.ASCE
    water administrator
    City of Tucson Water Department
    Tucson AZ