7/27/2019 White Paper on Roundabouts

http://slidepdf.com/reader/full/white-paper-on-roundabouts 1/2

7/27/2019 White Paper on Roundabouts

http://slidepdf.com/reader/full/white-paper-on-roundabouts 2/2

 

WSDOT and many local agencies are anxious to utilize this “new” design solution whereit will clearly solve problems. WSDOT in particular intends to venture cautiously

forward with their use of roundabout solutions and wishes to challenge any perception

that they are a cure-all for solving some very complex safety and operational issues. As

the knowledge base grows to include more operational experience, the selection criteriawill improve to more clearly identify the success factors associated with selection of a

roundabout design over a more “typical” stop-controlled or signal-controlled intersection

design.

The “Locations Not Normally Recommended for Roundabouts,” portion of Chapter 915

was intended to identify conditions where other solutions may be of equal or greater value than selection of a roundabout solution. While roundabouts may be considered

under the conditions listed, they must be very carefully evaluated, with equal

consideration of other intersection types.

CURRENT STATUSCurrent design standards, adopted under state law, require that the guidance in Chapter 

915 be followed, and for WSDOT, includes the level of oversight and approval specifiedin the chapter. Adhering to the approval processes specified in the chapter will allow

 practitioners to evolve in their knowledge and comfort level associated with selection of 

roundabouts in a consistent manner. As experience dictates, revisions to existingguidance and additional guidance will be incorporated into the chapter. Potentially, as

this guidance evolves, some of the approval steps may be relaxed, to streamline the

 process. In the interim, WSDOT and the City/County Design Standards Committee willcontinue to evaluate how the material is presented to determine if there are ways to

resolve some of the points of confusion.

 New research or evidence to suggest a change in policy is always welcome. Should you

learn of information that may influence our policies, please forward that information tothe WSDOT Design Office or the Highways & Local Programs Operations Office.