NorthEast Area Roundabouts Roundabout Primer & ideas

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Stafford, Ct WebCam Improve Safety & Traffic flow by 30 - 50%!! All old Circular Intersections can be "Retro-fitted" with FHWA/MUTCD approved Roundabout Lane Use signing & striping	Terms	Not all Circular Intersections are "Roundabouts"
	Capacities
*	Interchanges Double Roundabouts can be used on Interstate Exits! (Malta, NY plan for 2005) Other examples: Maryland Arizona Plan (pdf) Colorado	*
*	Several Types of Circular Intersection with 1-way traffic all the way around* Things in Road - post, fountain, flagpole, unknown :-)         No curbing - obscure date or origin, ~20ft dia. or less Rotary (-ies) - maybe same as above, but bigger, often with carved date (1880 to 1920), & stone curbing (under 50ft dia). "Classic" Traffic Circles - commonly 300ft, 600ft, rarely 100ft (buillt ~1930 to 1960) Decorative Circles - examples: ECSU by clock tower (Willimantic, Ct), Stafford Library (Ct) - the design firms won't discuss them :-) - cul de sacs (Windsor, Ct) Modern Roundabouts - built since 1980, ... * There are also countless old circles, ovals, triangles, rectangles with 2-way or mixed traffic legs, & marked by Yields, Stops, or Lights on 1 or more corners. Then there are the new "channelizing islands" (which I see as positive steps toward Roundabout acceptance!!)!	*

                Social Cost RatioSocial Costs for Signalized Intersection / Social Costs for Roundabout
{I am working on a simple theoretical model for this}
SCR for single lane ~21-42; & SCR for double lane ~4-6
SCR PPt Slide Show

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(reset 25 May'03) Prepared by RNWhite, NEAR(at)cox.net  in Summer 2003, revised Feb'05.