E N T E R P R I S E

Developing Consistency in ITS Safety Solutions – Intersection

Warning Systems

Project OverviewDecember 2011

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Agenda

• Project scope• Design and evaluation guidance• Roadmap to standardization• Questions

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Bring together organizations that have developed and deployed intersection

warning systems to develop a consistent approach for accelerated, uniform

deployment and further evaluation of intersection warning systems, and to recommend preliminary design and

evaluation guidance for MUTCD consideration.

Project Scope

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Project Scope

• Anticipated results– Increase awareness of systems deployed– Develop design guidance to support accelerated

and more consistent deployment– Establish evaluation framework – Create roadmap for reaching standards in MUTCD

and Highway Safety Manual

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Project Scope

• Webinar (June 23)– Shared knowledge and educated each other on

systems deployed• Missouri, North Carolina and Minnesota

– Identified challenges with future deployments• Warrants/Function • Liability• Placement • Failsafe/Reliability • Design • Capital and Operating Costs• Effectiveness • Connected Vehicle• Quality Control

Project Scope

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Project Scope

• Workshop #1 (July 28-29)– Discussed content of a preliminary standard

• Shift to design and evaluation guidance

– Discussed roadmap for reaching standardization• Engage further human factors research• Support further evaluation across state boundaries• Identify what may be required for interim compliance with

existing MUTCD standards• Allow for continued deployment and evaluation• Brief the NCUTCD and AASHTO SCOTE to initiate formal

processes

Project ScopeSign Roadway/Intersection Characteristics Sign/Detection Placement Message Set Results Other Notes

1. Minor Road

Iowa – Dyersville – US 20 (4-lane; 9,000 AADT) and 7th St (2-lane; 735 AADT)

Iowa – Anamosa – US 151 (4-lane; 10,050 AADT) and Old Dubuque Rd (2-lane; 1,385 AADT)

Problem: Gap acceptance

Missouri – Lowry City – MO 13 (4-lane; 10,000 AADT) and 1st St (2-lane)

Missouri – Osceola – MO 13 (4-lane; 10,000 AADT) and Truman Rd (2-lane)

Missouri – 8 other locations

Problem: Gap acceptance

Sign (with yellow flashers): 50-70’ to the left of STOP; on major road

Detection (loops): 1000’ before intersection on major road

TRAFFIC APPROACHING WHEN FLASHING

Missouri: Simple before/after study

32% reduction in all crashes 44% reduction in angle crashes 33% reduction in all severe crashes 8% reduction in all severe angle crashes

Isolated locations showed no improvement

Grid power with battery backup

Iowa: 2010 installations

$45,000 approximate cost per intersection

Missouri: 2008-09 installations

Determining acceptable gap for detector placement was challenging

2. Minor Road

Minnesota – Goodhue County – US 52 (4-lane; 17,500 AADT) and Co Rd 9 (2-lane)

Minnesota – Mille Lacs County – US 169 (4-lane; 11,200 AADT) and Co Rd 11 (2-lane)

Minnesota – Lyon County – MN 23 (4-lane; 6,200 AADT) and Co Rd 7 near Marshall

Wisconsin – Minong – US53 (4-lane; 4,400 AADT) and WI 77 (2-lane; 2,850 AADT)

Posted speed 65 MPH

Problem: Gap acceptance

Sign (DMS): First on far-side, opposite corner from STOP and second on far-side corner from median STOP/YIELD

Detection (radar): First approximately 800’ and second approximately 150’ before intersection

Symbol: Divided highway with color and do not enter indicators

Structured validation field test performed at Goodhue County site; included 48 participants from young, middle and senior age groups; additional 13 truck drivers completed study using a large truck

Data collected: rejected gap size, lead gap size, maneuver type (one-stage vs. two-stage), crossing and wait times, and safety margins

Overall, results indicated that participants used sign to reduce their risk level at intersection and that drivers had a positive opinion of the sign

Use of sign was associated with the rejection of shorter, unsafe gaps as evidenced by the increase in 80th percentile rejected gap

7.5 second critical gap threshold used by sign was shown to be in agreement with the driver’s gap selection performance

No apparent effect on intersection crossing metrics of accepted gap length, lead gap length, or time-to-contact.

Part of the USDOT Cooperative Intersection Collision Avoidance Systems (CICAS) and Rural Safety Improvement programs

Milles Lacs County site: Power cost estimated at $4,000-5,000 per year for full LED sign; could be less with addition of static sign

3. Minor Road

Minnesota – Hennepin County – Co Rd 47 (2-lane; 3,150 AADT) and Lawndale Ln (2-lane; 100 AADT)

Posted speed 40 MPH

Problem: Sight distance

Sign (with yellow LED arrow-shaped flashers): Far-side corner from STOP

Detection (radar): 750’ before intersection

LOOK FOR TRAFFIC Simple before/after study

54% reduction in traffic conflicts (sudden braking, sudden acceleration or swerving)

50% of survey respondents indicated they would pay more attention at intersection

Solar power with battery backup

4. Minor Road

Minnesota – Washington County – Manning Ave/CSAH 15 (2-lane) and McKusick Rd/CR 64 (2-lane)

Posted speed 55 MPH

Problem: STOP running

Sign (8 LED lights on STOP): At STOP

Detection (radar):

STOP, CROSS TRAFFIC DOES NOT STOP

Not yet available Commercial off the shelf sign

Railroad crossing immediately south of intersection

Alerts drivers of approaching stop ahead and to be more aware

5. Minor Road Georgia – Gwinnett County – Lester Rd (2-lane; 9,800 AADT) and Cutler Dr (2-lane residential)

Sign (with red flashers): Far-side, left from STOP

VEHICLE APPROACHING, IF NO LIGHT SIGNAL NOT

Lester Rd site showed preventable accidents went from 7 to 1 during three-year periods before/after installation

Installations done in 1999

Conducted by Gwinnett County

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Project Scope

• Workshop #2 (September 15-16)– Review preliminary design guidance– Develop an evaluation framework that may be

used in future deployments• Establish measures of effectiveness and data needs for

each system type to facilitate comparison of systems

– Discuss plans for future deployment and coordination plans

• Refined roadmap for standardization

• Introduction• Purpose• Typical system

components• Glossary of terms

Design and Evaluation Guidance

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Design and Evaluation Guidance

• Design guidance– Four typical layouts based on warning direction and

intersection configuration– Preliminary illustrations– Offer technical insight and recommended practice

• Do not limit engineering judgment or agency discretion

– Conditions, intended driver use, layout, options, notes and references

• More details conditions (warrants)• Anticipated benefits and costs

Design and Evaluation Guidance

• Evaluation guidance– Not all systems have been formally evaluated

• Acknowledged various evaluation approaches

– Establish a common framework for evaluation• Individual and national

– Based on ITS Evaluation Guidelines• Goal• Strategy• Hypotheses• Test plan parameters

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Roadmap to Standardization

2000 – 2011 Jun 2011 Jul 2011 Sep 2011 2012-13 2014

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Roadmap to Standardization

1. ENTERPRISE: Jon Jackels, MNa. Monthly board meetings; next is October 6, 2011b. Summarize webinar/workshop proceedings and guidance documentc. Request consideration of supporting national evaluation or ongoing

coordination role2. Design and Evaluation Guidance for ICWS: Athey Creek

a. Develop and distribute second draft week of October 17, 2011b. Develop support materials for summarizing webinar/workshop

proceedings and guidance3. FHWA MUTCD Team and Office of Safety: Jon Jackels, MNa. Small group webinar in late-October 2011b. Summarize webinar/workshop proceedings and guidance documentc. Identify what may be required for interim compliance with existing

MUTCD standards

Roadmap to Standardization

4. NCUTCD RWSTC: Tom Heydel (Matt Rauch), WIa. Meet January 18-19, 2012 during TRB in Washington, DCb. Summarize webinar/workshop proceedings and guidance documentc. Request consideration of task force to evaluate MUTCD prospectsd. Key members include Tom Heydel, WI and Bruce Ibarguen, ME5. AASHTO SCOTE: Bob Koeberlein (Gary Sanderson), ID

a. Likely to meet in January 2012 during TRB in Washington, DCb. Summarize webinar/workshop proceedings and guidance documentc. Request consideration of a recommendation to NCUTCDd. Key members include Bob Koeberlein, ID and Sue Groth, MN

6. ATSSA ICWS Industry Workshop: Jon Jackels, MNa. Proposed during ATSSA Annual Meeting, February 12 - 16, 2012 in Tampa, FLb. Summarize webinar/workshop proceedings and guidance documentc. Request industry response to key questions about ICWS product

development

Roadmap to Standardization

7. Traffic Control Devices Transportation Pooled Fund 5(065): Julie Stotlemeyer, MO

a. Annual meeting in April 2012 in KSb. Summarize webinar/workshop proceedings and guidance documentc. Consider human factors research of sign placement and message setd. Members include IA, KS, MO, NC and PA

8. Evaluation of Low Cost Safety Improvements Transportation Pooled Fund 5(099): Shawn Troy, NC

a. Annual meeting in March or April 2012b. Summarize webinar/workshop proceedings and guidance documentc. Consider coordination of national evaluationd. Members include IA, KS, MN, MO, NC, PA and WI

9. Others?a. ITE, International Municipal Signal Association, etc. b. Cooperative Transportation Systems TPF and Connected Vehiclec. FHWA-NCHRP Unsignalized Intersection Information Guide in 2012

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Questions?