The following presentation created by Kittelson & Associates, Inc. (KAI), provides an overview Modern Urban Roundabouts.

1. Modern Urban Roundabouts December 15, 2009

2. Roundabouts are a subset of circular intersections… Roundabouts Rotaries Neighborhood traffic circles All circular intersections Others

3. Rotary: US 377/TX 183/Camp Bowie Pkwy, Fort Worth, TX Photo: City of Fort Worth, TX

4. Conversion of Rotary to Roundabout: Kingston, NY Photo: New York State DOT

8. Pedestrian Access Photo: Oregon DOT Photos: Lee Rodegerdts Roundabout Traffic Circle

10. Direction of Circulation Photo: Ken Courage Photo: Lee Rodegerdts Roundabout Traffic Circle

11. Key Roundabout Features Exhibit 1-1, p. 6

12. Our recent history has been active… 1990 1995 2000 1905: Columbus Circle (NYC) 1990: First modern use in U.S. 1920s-1950s: Rotary era 2009-2010: Updated FHWA Rbt Guide, MUTCD, HCM 2005 2010 1990s: MD, FL, O&D Guides 2001-2007: Explosion of state guides and manuals 2000: FHWA Rbt Guide 2007: NCHRP Report 572

13. Number built each year is going up exponentially

14. U.S. sites by state through 1992

15. U.S. sites by state through 1997

16. U.S. sites by state through 2002

17. U.S. sites by state through 2007

20. Categories of Roundabouts

21. Mini-Roundabout

22. Mini-Roundabout Examples – U.S. Dimondale, MI Photo: Lee Rodegerdts Lutherville, MD Photo: Maryland SHA

23. Mini-Roundabout Examples - Europe Photo: Lee Rodegerdts Germany United Kingdom Photo: Werner Brilon

24. Urban Compact Roundabouts

25. Urban Compact Roundabout Examples West Boca Raton, FL Germany Photo: Lee Rodegerdts Photo: Werner Brilon

26. Urban Single-Lane Roundabouts

27. Urban Single-Lane Roundabout Examples Santa Barbara, CA Bend, OR Photo: Lee Rodegerdts Photo: Oregon DOT

28. Urban Double-Lane Roundabouts

29. Urban Double- and Multi-Lane Roundabout Examples Towson, MD Avon, CO

32. U.S. Experience NCHRP Report 572 Results (May 2006) 82 44 Two-way stop (36) No significant change No significant change All-way stop (10) 78 48 Signalized (9) 76 35 All sites (55) % Reduction in Injury Crashes % Reduction in All Crashes Group Characteristic before Conversion (sample size)

33. Maryland’s Roundabout Accident Experience (March 2007 Study) Accident data at 15 state highway intersections converted to single-lane roundabouts between April 1993 and December 2003 86% reduction 0.16 1.13 Mean injury accident rate (acc./MEV) 68% reduction 0.61 1.91 Mean total accident rate (acc./MEV) 83% reduction 7.3 43.5 Total annual injury accidents 65% reduction 24.8 71.7 Total annual accidents % Change After Before

35. Lower speed is safer for pedestrians Chance of pedestrian death increases with vehicle speed Source: United Kingdom

37. Vehicle Conflict Points: REDUCED Crossing conflicts eliminated at roundabout Merging Diverging Crossing

40. Roundabouts versus Signals: MUTCD Signal Warrant Threshold 0 2 4 6 8 10 12 14 16 18 20 600 700 800 900 1000 1100 1200 1300 1400 1500 Total Major Street Volume (veh/h) Average Delay (s/veh) Signal (10% left turns) Signal (50% left turns) Roundabout (10% left turns) Roundabout (50% left turns) Exhibit 3-7, p. 63 Based on MUTCD Warrant 3 (2000 ed.)/Warrant 11 (1988 ed.)

42. Example of Land Use: Clearwater, FL Photo: City of Clearwater, FL Commercial w/ angle parking Residential

45. Design vehicle Photos: Lee Rodegerdts Truckee, California Portland, Oregon

52. Pedestrian hybrid signal: Golden, CO Photo: Lee Rodegerdts

54. Example Bicycle Treatments

55. Bicycle Treatments: Grand Junction, CO Source: City of Grand Junction, CO

57. NCHRP Synthesis 264 (Jacquemart) Before Construction After Construction

58. Project Techniques: Public meeting displays Model created by Missouri D.O.T. Photo: Missouri DOT

59. Project Techniques: Educating School Age Children (Overland Park, KS) Photo: Erin Ferguson

60. Project Techniques: Brochures (Vail, CO) Exhibit 2-6(a), p. 42

62. Sample State Web Site: Maryland State Highway Administration

63. La Jolla Boulevard – Bird Rock Roundabouts

65. Case Study – Campus Drive/Daggett Avenue N Opportunities to improve ped/bike facilities Minimal ROW needs Reduction to one travel lane Roundabout? Example ped/bike improvements

67. Thank You! Photo courtesy of Harper Houf Peterson Righellis, Inc.