07-03-2011, 10:51 AM
quote:
Originally posted by DTisme
[quote] in Washington, D.C., where roundabouts go back to L'Enfant's original 1789 design.
No, those ARE NOT ROUNDABOUTS IN D.C.
Those are TRAFFIC CIRCLES and NOT the same as roundabouts.
Design of splitter islands and yield on entry are basic differences.
Same for the "merge" bit above -- that IS NOT what happens at a roundabout.
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... try these links to learn what a roundabout actually is...
www.alaskaroundabouts.com/index.html
www.tfhrc.gov/pubrds/fall95/p95a41.htm
www4.nationalacademies.org/trb/onlinepubs.nsf/web/NCHRPSynthWeb)
www.tfhrc.gov/safety/00068.htm
www.dot.state.ny.us/roundabouts/howto.html
www.engr.orst.edu/~taekrtha/round.html
www.abnaengineering.com/abna
www.ksu.edu/roundabouts/
www.tfhrc.gov/safety/00068.htm
www.akcelik.com.au/SIDRA/roundabouts.htm
www.ksu.edu/roundabouts
www.roundabouts.net/roundabouts.html
www.azdot.gov/CCPartnerships/Roundabouts/PDF/Traffic_Speed.pdf
www.dot.state.az.us/CCPartnerships/Roundabouts/faq.asp
www.ite.org/traffic/documents/tcir0019.pdf
www.ci.davis.ca.us/pw/traffic/roundabouts.cfm
depts.washington.edu/hiprc/practices/topic/pedestrians/environment.html
www.citebc.ca/No95_Roundabout.html
www.findarticles.com/p/articles/mi_qa3734/is_200209/ai_n9139900
www.walkinginfo.org/de/curb1.cfm?codename=16c&CM_maingroup=Intersection%20Design
www.sdearthtimes.com/et0501/et0501s12.html
www.apwa.net/Publications/Reporter/ReporterOnline/index.asp?DISPLAY=ISSUE&ISSUE_DATE=072000&ARTICLE_NUMBER=130
www.insurancejournal.com/magazines/southcentral/2000/08/14/features/22640.htm