ITE Working Group on Roundabout Accessibility Issues

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ITE Working Group on Roundabout Accessibility
Issues
ROUNDABOUTS
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A roundabout...

• is an intersection with a generally circular
  shape.
• requires all entering traffic to yield to
  circulating traffic.
• has appropriate geometric features to ensure
  slow entering and circulating speeds.

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Roundabouts are a subset of circular
intersections
All circularintersections
Roundabouts
Others
Rotaries
Neighborhoodtraffic circles
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Conversion of Rotary to RoundaboutKingston, NY
Photo New York State DOT
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Key Roundabout Features
Exhibit 1-1, p. 6
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Roundabouts versus Traffic Circles

• Five key elements distinguish roundabouts
• YIELD control on entry
• Priority to circulating vehicles
• Pedestrian access crossing
• Parking
• Direction of circulation

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Speed Reduction
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Speed Reduction
Little Deflection
Adequate Deflection
Photos Lee Rodegerdts
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Settings

• Mini-roundabouts
• Urban compact
• Urban single-lane
• Urban double-lane
• Rural single-lane
• Rural double-lane

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Mini-Roundabout ExamplesGermany
Photos Werner Brilon
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Urban Compact RoundaboutGermany
Photo Werner Brilon
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Urban Single-Lane RoundaboutBend, OR
Photo Oregon DOT
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Urban Double-Lane RoundaboutClearwater, FL
Photo Bruce Robinson
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Urban Multi-Lane RoundaboutAvon, CO
Photo Lee Rodegerdts
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Rural Single-Lane RoundaboutLeeds, MD
Photo Maryland SHA
Photo Lee Rodegerdts
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Rural Double-Lane Roundabout Examples
Taneytown, MD
Photo Lee Rodegerdts
Photo Austroads
Australia
Photo Eenheid in Rotondes, CROW
Utrecht Province, The Netherlands
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Typical Settings and Reasons for Implementation

• Community Enhancements
• Traffic Calming
• Safety Improvements
• Operational Improvements
• Special Situations

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Community Enhancements
Located in areas where capacity and safety are
not key issues
Photo Lee Rodegerdts
Photo Joe Bared
France
Naples, FL
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Traffic Calming
Used for speed control in neighborhoods
Photo Lee Rodegerdts
Naples, FL
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Geography

• International
• - 50,000
• - 15,000 in the UK and France
• US
• - 252 minimum
• - likely more than 500

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252 US Roundabouts

• 174 (69) single lanes
• 56 (22) are multi-lane
• 22 (9) unknown

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A brief history of roundabouts
1997 Added to HCM
1905 Columbus Circle in NYC
1990 First modern use in U.S.
1966 Mandatory give-way rule adopted in
UKFirst modern use in UK
1900
1950
2000
1970s First modern use in France, Australia
1920s-1950s Rotaries built in U.S.
1980s First modern use in Germany
2000 FHWAs ROUNDABOUTS An Informational Guide
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NCHRP Synthesis 264 (Jacquemart)
Before Construction
After Construction
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ITE Journal, Sept. 2002 (Retting, et al.) Survey
in KS, MD, and NV
Before Construction
After Construction
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Pedestrian / ADA Issues

• Positives
• Speed-controlled environment
• Splitter island provides refuge
• Negatives
• Pedestrians must assess gaps
• Disabled, children, and elderly may have
  difficulty
• Entries and exits with more than one lane are
  difficult to cross

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Pedestrians

• General Principles
• Discourage use of central island
• Crossing set back from the yield line
• Splitter islands
• Perpendicular crossings

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Visually Impaired Pedestrians

• Navigation tasks
• Locating the crosswalk
• Listening for a safe gap
• Splitter island pedestrian refuge
• Locating the correct path after the crossing

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Pedestrian Crossing Design
Exhibit 6-26, p. 157
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Sidewalk Design
Exhibit 6-40, p. 169
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PedestriansEurope
Source Werner Brilon
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PedestriansAnnapolis, MD
Photo Ed Myers
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Multi-modal TreatmentsThe Netherlands
Separate bicycle track/path
Good Solution safe higher volumes
Source Rotondes - CROW
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Multi-modal TreatmentsThe Netherlands
Ped/Bike Priority (urban areas)
Vehicle Priority (rural areas)
Source Eenheid in Rotondes - CROW
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Visually Impaired Pedestrians

• Design Guidance
• Optimal location of crosswalk
• Optimal orientation of crosswalk
• Application of textured pavements
• Raised crosswalks
• Traffic Control
• Other guidance issues

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Visually Impaired Pedestrians

• Technological Advancements
• Flashing beacons
• Raised Crosswalks
• In-pavement flashers
• Pedestrian signals (midblock, actuated, ped
  activated)
• WMU research