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Post Construction

Page history last edited by Frank Broen 11 years, 1 month ago

Date:    Wed, 6 Feb 2013 08:38:49 -0700

From:    Phil Demosthenes <pdemos@ECENTRAL.COM>

Subject: When roundabouts have high crash rates

 

While some good things are stated below about these roundabouts with high crash rates, I still think there must be a way through post-construction operational assessments to improve a roundabout safety performance. It is rarely the fault of the design; it's most always the fault of the driver. But what the roundabout design process offers the highway agency is the opportunity to design a roundabout that will accommodate typically poor driver behavior which is the reason I strongly support roundabouts. They can be designed with people in mind. Signals are just stop or go and the rest is up to the motorist  -- While roundabouts allow continuous flow and if designed with human factors/behavior in mind, can be much safer with excellent capacity.

 

The best example is the big, high volume infamous one in Clearwater FL. Initial poor design resulted in about 260 crashes in first 6 months. The design was fixed (thank you Barry Crown, RODEL) and now only a few crashes a year. And more importantly, of the 260 none were reported as severe injuries. Unlike signals, post construction operational review should be assumed as part of the installation process and budgeted/scoped/contracted if you want top performance from an arterial roundabout, especially multi-lane.

 

Here is a thought. While we frequently discuss motorist human factors in crashes, with roundabouts we also need to focus on the human factors of the designers and engineers. The design process, with roundabouts, is a key contributor to the success or lack of success of a completed roundabout. 

 

ANYWAY - HERE IS THE LINK TO THE WISCONSIN ARTICLE.

"Roundabouts top locations with most crashes; injuries not as severe"

 

http://www.thenorthwestern.com/article/20130204/OSH0101/302040168/Roundabouts-top-locations-most-crashes-injuries-not-severe?nclick_check=1

 

 

The intersections in Oshkosh where the most crashes occur are roundabouts, but the severity of crashes has decreased since the intersections where converted from traditional intersections into roundabouts.

 

Roundabouts on the U.S. Highway 41 frontage road at Washburn and Koeller streets, along with the roundabout at Murdock Avenue and Jackson Street were the top five intersections in the city with the most crashes in 2012.

 

Of the 2,585 traffic crashes Oshkosh police responded to in 2012, 293 were at the frontage road roundabouts at West Ninth and Witzel avenues, according to an analysis The Oshkosh Northwestern completed of crash data provided by the Oshkosh Police Department.

 

“That doesn’t surprise me at all, with the amount of traffic that was diverted from Highway 21 over to those intersections,†said Joe Nichols, spokesman for the Oshkosh Police Department.

 

The Highway 41 interchanges at Witzel and West Ninth avenues experienced increased traffic flow from late March through late October while the interchange at State Highway 21 was closed for reconstruction. During that time period, 222 of the crashes at the roundabouts occurred, including 12 of the 13 crashes in 2012 involving injuries.

 

The roundabout at West Ninth Avenue and South Washburn Street, which has 18,500 vehicles pass through daily according to Wisconsin Department of Transportation traffic counts, tops the list of worst intersections with 94 reported crashes in 2012, including three with injuries.

 

Eighty-six crashes were reported at South Washburn Street and Witzel Avenue, where 9,500 vehicles travel daily, and 73 were reported at South Koeller Street and West Ninth Avenue, where 19,200 vehicles pass through daily. There were 50 crashes in the roundabout at Jackson Street and Murdock Avenue.

 

Phil -  303-349-9497

phil@pdemos.com


Date:    Wed, 6 Feb 2013 13:30:19 -0500

From:    "Jay J. Vorisek" <jvorisek@CROSSROADENGINEERS.COM>

Subject: Re: When roundabouts have high crash rates

 

Sometimes it's the fault of the design guidance given to the designer.

Here's a quote from the 2000 FHWA Roundabout Information Guide, page 200,

first paragraph under section 7.2.3 "In general, lane lines should not be

striped within the circulatory roadway, regardless of the width of the

circulatory roadway. Circulatory lane lines can be misleading in that they

may provide a false sense of security."

 

Jay Vorisek, P.E.

 

-----Original Message-----

From: Roundabout Research [mailto:ROUNDABOUTS@LISTSERV.KSU.EDU] On Behalf Of

TONY Redington

Sent: Wednesday, February 06, 2013 11:34 AM

To: ROUNDABOUTS@LISTSERV.KSU.EDU

Subject: Re: When roundabouts have high crash rates

 

Hi Phil:

Interesting that you first suggest crashes are "rarely the fault of the

design" and then bring up Clearwater which clearly was an error of design.

Design may be perfect but inappropriately applied--the Kitchener roundabout

with an extra lane not justified with initial traffic volumes, ditto for a

right turn slip lane from south to east at Keene Turn Brattleboro (VT).  The

majority of crashes at the Keene Turn (1999) are absolutely a design defect

that the Agency of Transportation to this day refuses to remedy resulting in

fender benders involving large commercial vehicles. Yet, injuries dropped

95% from 55 to 1 before and with about five years before and after data.

Here the property damage crashes before and after did not reflect any real

safety concern, but one of design.  Sad, since all the costs involved mostly

commercial vehicles.

 

Oshkosh presents a completely inadequate amount of information to comment.

No before and after injury data by type and property damage only crashes do

not much reflect safety one way or another.  Property damage crashes may

indicate design defects.

 

                                            Tony

Christopher K.

Sent: Wednesday, February 06, 2013 9:59 AM

To: ROUNDABOUTS@LISTSERV.KSU.EDU

Subject: Re: When roundabouts have high crash rates

 

As an (only?) Oshkosh resident on this list-serve, let me chime in on the discussion.

 

For those who don't know our community, we have a freeway (US 41) that bisects the City, and five different streets cross over it south of the Fox River: Highway 44, 20th Avenue, 9th Avenue, Witzel Avenue and Highway 21.  (Try http://goo.gl/maps/Qhxpu.)  All but Highway 44 and 20th Avenue now have roundabouts at the freeway and/or adjacent frontage roads.  The Witzel Avenue roundabouts opened in 2010, the 9th Avenue ones in 2011, and the Route 21 ones in 2012. 

 

With respect to our experience in 2012, the perception is that some in the community were paranoid about roundabouts, and so stayed on Route 21 to avoid going through roundabouts on Witzel and 9th.  The 2012 construction took away that option, and so there were quite a few drivers who were forced into roundabouts who maybe had little or no previous experience with them. 

 

With respect to causality, I've attached an annual study that analyzes high crash locations in the City; this is looking at 2011 data.  Pages 3 through 5 of the report focus on our roundabouts.  The 2012 report will be out in a couple of months. 

 

Thanks,

-Chris

 

-------------------------------------------------

Christopher Strong, P.E.

Director of Transportation

City of Oshkosh

926 Dempsey Trail

Oshkosh, WI 54902

Phone: (920) 232-5342

E-mail: CStrong@ci.oshkosh.wi.us

 

 

 

-----Original Message-----

From: Roundabout Research [mailto:ROUNDABOUTS@LISTSERV.KSU.EDU] On

Behalf Of dot.sm.mo.roundabouts

Sent: Wednesday, February 06, 2013 10:53 AM

To: ROUNDABOUTS@LISTSERV.KSU.EDU

Subject: Re: When roundabouts have high crash rates

 

Phil,

 

While I completely agree that Barry greatly improved the design of

Clearwater, I don't see how RODEL had any part in the improvement.  I

would even go as far as to say that quite a few of the improvements,

like reducing the number of circulating lanes and dedicating certain

destinations to specific approach lanes, aren't even acknowledged by

RODEL.

 

Regarding the Oshkosh roundabouts, hopefully the influx of Route 21

traffic really did contribute to the higher than desired accident

numbers since the design was done by a highly regarded roundabout design

firm.

 

Thease roundabouts could be the base of a good paper/presentation for

Seattle... :-)

 

Regards,

 

Howard

 

 

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