dye road and court street roundabout construction

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


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


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.



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


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


Brighton MichiganNorth

3rd St.

Main St.

66 ft. ROW

55 ft. ROW


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


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


..

The Real Benefit


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


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


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


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


LocationNorth

Dye Rd.

Court St.

100 ft. ROW

66 ft. ROW

83 ft. ROW


Roundabout Acceptance

BEFORE:68% Against AFTER

73%For


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


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


Additional Project ParticipationNon-monetary

This is a new traffic control device

Requires public media involvement to education our driving public


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


Thank youFred Peivandi, County Highway Engineer

Ken Jonson, Program Development EngineerGenesee County Road Commission

(810) 767- [email protected]

mailto:[email protected]


Video Simulation• Four Way Stop Operation

• Roundabout Operation

dye road and court street roundabout construction

Documents

roundabout entrance

miller road linden rd

injury crash frequency

total crash frequency

peak hourseptember

peak hour traffic backups

highway safety

south bound stop sign