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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. PRESENTATION. Concerns with Dye Rd. & Court St. Intersection What are roundabouts? Fundamentals - PowerPoint PPT Presentation
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September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Dye Road and Court Street Roundabout Construction
John Daly, Manager-DirectorFred Peivandi, County Highway EngineerKen Johnson, Program Development Engineer Genesee County Road Commission
September 24, 2012Genesee 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
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, 2012Genesee County Road Commission Dye & Court Roundabout
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, 2012Genesee County Road Commission Dye & Court Roundabout
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Yield Line
Inscribed Circle Diameter
Central Island
Entry
Circulating Road
Splitter Island Exit
Pedestrian Crossing
September 17, 2012
Bennett Rd. & Hulett Rd Intersection Ingham County
Bennett Woods Elementary
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Design ElementMini- Roundabout Urban
CompactUrbanSingle-Lane
UrbanDouble-Lane
RuralSingle-Lane
RuralDouble-Lane
Recommended 25 km/h 25 km/h 35 km/h 40 km/h 40 km/h 50 km/h
maximum entry (15 mph) (15 mph) (20 mph) (25 mph) (25 mph) (30 mph)
design speed
Maximum number of entering lanes
1 1 1 2 1 2
per approach
Typical inscribed 13 m to 25 m 25 to 30 m 30 to 40 m 45 to 55 m 35 to 40 m 55 to 60 m
circle diameter1 (45 ft to 80 ft) (80 to 100 ft) (100 to 130 ft) (150 to 180 ft) (115 to 130 ft) (180 to 200 ft)
Splitter island Raised if Raised, with Raised, with Raised, with Raised and Raised and
treatment possible, crosswalk cut crosswalk cut crosswalk cut extended, with extended, with
crosswalk crosswalk cut crosswalk cut
cut if raised
Typical daily service volumes on 4-leg
10,000 15,000 20,000 Refer toChapter 4
20,000 Refer toChapter 4
roundabout (veh/day) procedures procedures
1.6.1 Comparison of roundabout categoriesExhibit 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
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Brighton MichiganNorth
3rd St.
Main St.
66 ft. ROW
55 ft. ROW
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Roundabout SafetyPersaud 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
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
NCHRP Report 572 – Roundabouts in the USBefore-after studies at 55 intersections
• 35% overall decrease in crashes
• 76% decrease in injury crashes
• 81% decrease in fatal/incapacitating crashes forsingle lane urban roundabouts
• 71% decrease in fatal/incapacitating crashes forsingle lane rural roundabouts
Many other studies with similar results
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
..
The Real Benefit
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Roundabout CongestionReduction
By definition – Traffic entering a roundabout does not have to stop, but yields when entering
More vehicles can occupy the intersection at one time4 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
September 24, 2012Genesee 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
January 29, 2008Genesee County Road Commission
Non-motorized Project Coordination
NY State Study Roundabout vs. Signalized intersection
September 24, 2012Genesee 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
September 24, 2012Genesee 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 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
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
LocationNorth
Dye Rd.
Court St.
100 ft. ROW
66 ft. ROW
83 ft. ROW
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Roundabout Acceptance
BEFORE:68% Against AFTER
73%For
September 24, 2012Genesee 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
September 24, 2012Genesee 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
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Additional Project ParticipationNon-monetary
This is a new traffic control device
Requires public media involvement to education our driving public
September 24, 2012Genesee 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
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Thank youFred Peivandi, County Highway Engineer
Ken Jonson, Program Development EngineerGenesee County Road Commission
(810) 767- 4920kjohnson@gcrc.org
September 24, 2012Genesee County Road Commission Dye & Court Roundabout
Video Simulation• Four Way Stop Operation
• Roundabout Operation
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