General Roundabout Overview

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General Roundabout Overview
NEW YORK STATE DEPARTMENT OF
TRANSPORTATION
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What is a Roundabout?It is a type of
intersection control, just as signals and
stopsigns are examples of intersection control.
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Example of Signal Controlled Intersection
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Roundabouts are circular intersections designed
so that 1. Entering traffic must yield to
circulating 2. Entering vehicles are deflected
by splitter islands, creating a low /
similar speed environment 3. Circulating
vehicles must travel around a non-mountable
center island.
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Leading Roundabout States
Colorado gt 240 Washington gt 150 Utah
gt 110 Maryland gt
100 North Carolina gt 90 Oregon gt
75 Florida gt 50 Kansas Missouri gt 45
each California Nevada gt 30 each Arizona
gt25 New York at least 54, with gt 90 in design
throughout the state
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New York Roundabouts Single Laners
North Haven (01) single laner that was to be 1 of
2 Rochester (03) single laner on RIT campus Great
Neck (03) single laner that replaced signalized
circle Voorheesville (03) single laner that
replaced yield Y Greenwich (04) single laner
that replaced signalized T Ithaca (04) single
laner off state system Plattsburgh (04) single
laner that replaced signalized 4-way Liberty
(2) (06) single laners off Exit 100,
I-86 Cortlandt Manor(06) single laner that
replaced signal Huntington (02) single laner used
for traffic calming Rochester (05) single laner
with raised pedestrian crossing
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New York Roundabouts Single Laners
Mt Vernon (06) single laner with fountain and
music Mendon (06) single laner with center light
hi-speed Stony Brook, LI(06) single laner on
campus roadway Poughkeepsie (3)(06/08) single
laners near Vassar College Bethlehem (07) single
laner that replaced a 3-way stop Bainbridge (07) s
ingle laner just off I-88 exit w/NY 206 Hamburg
(4) (07/08) urban single laners made of 100
PCC Westchester Airport (06) access to local
airport Westhampton Beach (06) oval single laner
at former 6 corners Eastern LI (07)
local intersection designed by McLean Colonie
Center (07) access to mall from town road Glens
Falls (07) 5 legs in urban, downtown
environment
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New York Roundabouts Single Laners
Malta (08) single laner for Round Lake
Bypass Cohoes (08) single laner at 3
corners Niagara Falls (07) single laner on
Rainbow Boulevard Malta (2) (08) single
laners on Dunning St. for Tech Parks Buffalo
(2) (08) single laners that are only 100
apart Caledonia (05) resigned restriped traffic
circle
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New York Roundabouts Major/Minors
Kinderhook (05) 2 laner for SB direction only, 5
legs Buffalo (08) Harlem/Cleveland Road Corning
(2) (03) access permits for R D
plant Latham (02) resigned restriped
traffic circle Griffiss (02) major-minor done in
old air force base
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New York Roundabouts Two Laners Kingston (00)
2 laner that replaced traffic circle Malta (5) (06
) 5 total in a ¾ mile corridor Johnson City
(05) 2 laner flyover that replaced traffic
circle Slingerlands (4) (07) 4 total in a 1.5
mile section of new hwy
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New York Roundabouts In Construction
Round Lake major-minor _at_ Rt 9/67 Rotterdam singl
e laner _at_ 7/146 Batavia single laner _at_
33/98 Irondequoit (4) single laners at end of
590 Buffalo major-minor on Outer Harbor
project Aurora resigned and restriped single
lane circle
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New York Roundabouts In Final Design
Latham Old Wolf _at_ Old Nisky Malta (2) a single
major-minor for AMD Monticello single laner _at_
104 off 17B Mayfield major-minor _at_ 29 30 East
Greenbush Route 4 _at_ 151
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New York Roundabouts In Design
Auburn railroad right thru center
island Brockport single laner with ROW
constraints Cicero Onondaga County
project Glenville Maple _at_ Glenridge Road
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Why are Roundabouts Being Considered?

• Safest Intersection
• High Capacity / Low Delay
• Good for All Modes of Traffic
• Geometric Flexibility
• Aesthetics

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(No Transcript)
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2004 Safety Data from Maryland DOT

• Reduction of Total Crashes by 68
• Reduction of Property Damage Only Crashes
  by 41
• Reduction of Injury Crashes by 86
• Reduction of Fatal / Incapacitating
  Crashes by 100
• This resulted in a B/C analysis that indicated
  for every dollar spent on these projects,
  considering the 15-year service life of the
  roundabouts, there is a return of approximately
  15.00 to be realized through accident reduction.

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Roundabouts Reduce Crashes!!!
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Roundabouts Reduce Crossing Conflicts
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Roundabouts Make Crossings Safer
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NYSDOT Pedestrian Guidance Video
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Village of Great Neck, Long Island
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High s of Peds Cross from LIRR
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(No Transcript)
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Unless All Red Signals Provide No
Protected Pedestrian Phase
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Crossing at the Signal Safer?
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NYSDOT Bicyclist Guidance Video
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Young Bicyclist at Voorheesville Roundabout
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Pedestrians / Bikes Safety Summary

• Zero SEVERE Injury or Fatal Ped/Bike Crashes at
  any U.S. High Capacity Multi-Lane or Single-Lane
  Roundabout
• Approximately 13 non-injury since 1993
  (8 cyclists, 5 pedestrians)

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NYSDOT Single Lane Roundabout Signing
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Adding a Signal Doesnt Always SafetyThe
Leader Herald April 22nd, 2005
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Red Light Running Cameras
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A North American Perspective
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A European Perspective

• Photo Matthew Enders, WSDOT

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Public Involvement

• Public resistance is common
• Before construction 3 to 2 against roundabout
• Education is crucial
• After construction 4 to 1 in favor of roundabout
• Visualizations are very helpful

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Common Objections Snow Removal Greenwich, NY
Roundabout
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Common Objections Large Trucks
75x13 Modular Home Takes Left at Greenwich, NY
Roundabout
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Common Objections School Area Valatie
Roundabout
Sherrill Phillips, Supervisor of Transportation
for the Ichabod Crane School District (28 buses)
"Very pleased with the roundabout there are no
problems reported from any of their bus
drivers." "Red light running was common before
with the signal, especially from Rt 9
South." "Students crossing from the school
(south of roundabout) have a safer crossing
due to the traffic calming effect."
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Public Opinion WILL Change
The director of the Charles R. Wood Theater said
she was skeptical when the Greenwich roundabout
was first talked about. "I'm not an expert on
traffic, but I was convinced it wasn't going to
work out," she said. Now, she describes driving
through the circular intersection as an "awesome
experience. "I guess sometimes you just have to
trust the opinions of traffic experts," she said.
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Roundabout Solutions Glen Bay Streets, Glens
Falls - 5 leg urban
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Roundabout Solutions The Batavia roundabout in 20
years
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The NYSDOTRoundabout Design Unit would like to
thank everyone for their attendance this
beautiful eveningQuestions? Comments?
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NYSDOT Roundabout Design Unit Contact Information

• Richard Schell, PE
• Howard McCulloch,
• and Tom Kligerman, PE
• Roundabout Design Unit
• 50 Wolf Road, POD 24
• Albany, New York 12232
• Tel [phone]
• Fax [phone]
• E-mail roundabouts_at_dot.state.ny.us