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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Dye Road and Court Street Roundabout Construction John Daly, Manager-Director Fred Peivandi, County Highway Engineer Ken Johnson, Program Development Engineer Genesee County Road Commission
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout PRESENTATION Concerns with Dye Rd. & Court St. Intersection What are roundabouts? Fundamentals Why a roundabout here? Project Schedule Cost Participation
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Dye Rd. & Court St. Concerns -A major fatality occurred in 2010 with a driver ignoring the south bound stop sign. -Between 2006-2010 28 minor crashes -Two southbound stop sign violations observed during the peak hour -Traffic Backups during peak hour September 24, 2012 Genesee County Road Commission Dye & Court Roundabout
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What are Roundabouts? A circulating roadway at an intersection which: Is NOT a traffic circle Roundabouts are smaller Low speeds (15-20 MPH) Entering vehicles must always yield to circulating traffic Entrances are angled (deflected) forcing vehicles to slow down Pedestrian crosswalks are before roundabout entrance. September 24, 2012 Genesee County Road Commission Dye & Court Roundabout
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout September 17, 2012 Bennett Rd. & Hulett Rd Intersection Ingham County Bennett Woods Elementary
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout
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September 24, 2012September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Design Element Mini- Roundabout Urban Compact Urban Single-Lane Urban Double-Lane Rural Single-Lane Rural Double-Lane Recommended25 km/h 35 km/h40 km/h 50 km/h maximum entry(15 mph) (20 mph)(25 mph) (30 mph) design speed Maximum number of entering lanes 1 1 1212 per approach Typical inscribed13 m to 25 m13 m to 25 m 25 to 30 m25 to 30 m 30 to 40 m30 to 40 m45 to 55 m45 to 55 m35 to 40 m35 to 40 m55 to 60 m55 to 60 m circle diameter 1 (45 ft to 80 ft) (80 to 100 ft) (100 to 130 ft)(100 to 130 ft)(150 to 180 ft)(150 to 180 ft)(115 to 130 ft)(115 to 130 ft)(180 to 200 ft)(180 to 200 ft) Splitter islandRaised if Raised, with Raised and treatmentpossible, crosswalk cut extended, with crosswalkcrosswalk cut cut if raised Typical daily service volumes on 4-leg 10,000 15,000 20,000 Refer to Chapter 4 20,000 Refer to Chapter 4 roundabout (veh/day)procedures 1.6.1 Comparison of roundabout categories Exhibit 1-7 summarizes and compares some fundamental design and operational elements for each of the six roundabout categories developed for this guide. The following sections provide a qualitative discussion of each category. Exhibit 1-7. Basic design characteristics for each of the six roundabout categories. 1. Assumes 90-degree entries and no more than four legs. Federal Roundabout Classifications FHWA Informational Guide – RD-00-067
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Brighton Michigan North 3 rd St. Main St. 66 ft. ROW 55 ft. ROW
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Roundabout Safety Persaud et. al. (Insurance Institute for Highway Safety), 2000 (U.S.) of 23 U.S. intersections converted from stop/signal to roundabouts it was revealed: *40% reduction in total crash frequency *80% reduction in injury crash frequency *90% reduction in fatal/incap. injury crash frequency Maryland DOT Accident Evaluation, 2004 *~15:1 benefit – cost ratio for installation of single lane roundabouts Multi-lane roundabouts see crash rates approach those of signals, but severity is lower Michigan Department of Transportation *76% reduction in severe injuries *39% reduction in minor crashes
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout NCHRP Report 572 – Roundabouts in the US Before-after studies at 55 intersections 35% overall decrease in crashes 76% decrease in injury crashes 81% decrease in fatal/incapacitating crashes for single lane urban roundabouts 71% decrease in fatal/incapacitating crashes for single lane rural roundabouts Many other studies with similar results
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout.. The Real Benefit
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Roundabout Congestion Reduction By definition – Traffic entering a roundabout does not have to stop, but yields when entering More vehicles can occupy the intersection at one time 4 way stop allows only one vehicle at a time Vehicles can enter simultaneously from all approaches compared to two approaches at a signalized intersection Gaps between vehicles can be used by waiting vehicles coming in from all directions
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Emissions and Fuel Consumption Reduction Fewer emissions Less idling Less pollution No electricity compared with signalized intersection Less Fuel consumed Less Severe Accelerations and Braking Smaller carbon footprint
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January 29, 2008 Genesee County Road Commission Non-motorized Project Coordination NY State Study Roundabout vs. Signalized intersection
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Why a Roundabout Here? Road Commission has been impressed with the roundabout crash and congestion reduction statistics. Have looked at other locations Flint Township has expressed an interest in a roundabout intersection Dye & Court - locally classified roadway which limits funding. Crash history qualifies for Federal Safety Funds A roundabout will reduce crashes, delay time, congestion, fuel consumption, emissions and traffic backups
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Due to the crash history a Roundabout will provide $56,711 of crash reduction benefits per year Most effective crash reduction countermeasures Crashes Crashes Cost Cost For an estimated $231,000 construction cost the roundabout will pay for itself in 4 years A Roundabout Here pays for itself in 4 years
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Location North Dye Rd. Court St. 100 ft. ROW 66 ft. ROW 83 ft. ROW
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Roundabout Acceptance BEFORE: 68% Against AFTER 73% For
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September 24, 2012September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Project Schedule Road Commission will hold another public meeting Township will take action on a draft agreement Design consultant will be selected Project design this coming winter Project was selected for funding for the 2013 fiscal year Construction in the summer of 2013 w/ Dye Road
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Project Cost Participation Construction Cost Estimated at $231,000 Federal Aid will contribute 90% or $ 207,900 Road Commission – Engineering & Inspection $58,000 Flint Township – Local Match - $23,100 TOTAL PROJECT COST $289,000
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Additional Project Participation Non-monetary This is a new traffic control device Requires public media involvement to education our driving public
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout In Summary Dye Rd. & Court St. – crashes, backups Roundabouts – unique countermeasure -reduces crash injuries & frequency -reduce congestion, fuel consumption and emissions Roundabout are not just an engineering novelty, but the most effective traffic control countermeasure which solves the problems at this intersection
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Thank you Fred Peivandi, County Highway Engineer Ken Jonson, Program Development Engineer Genesee County Road Commission (810) 767- 4920 kjohnson@gcrc.org kjohnson@gcrc.org
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September 24, 2012 Genesee County Road Commission Dye & Court Roundabout Video Simulation Four Way Stop Operation Roundabout Operation
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