A Systemic Approach to Safety Management

NLTAPA Annual ConferenceJuly 30, 2012

Hillary Isebrands, P.E., PhD

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Welcome and Introductions

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Overview

• Introduction to the systemic approach to safety

• Explain how it can be applied in local jurisdictions

• Illustrate how the systemic approach can be used through state and local case studies

• Describe how to advance the systemic approach to safety in your state

What we mean by “systemic safety improvement”

• An improvement that is widely implemented based on high-risk roadway features that are correlated with particular severe crash types. • The systemic approach is intended to complement the traditional site analysis approach (i.e. high crash locations) resulting in a comprehensive safety management program.

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What we mean by “risk”

The potential for a specific type of severe crash to occur at a specific location because of the location’s characteristics or features.

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What we mean by “risk factor”A representation of risk in terms of the observed characteristics associated with the locations where the targeted crash types occurred • Volume• Alignment• Intersection control• Presence of shoulders

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Potential Risk FactorsRoadway FeaturesNumber of lanesLane widthShoulder surface width/typeMedian width/typeHorizontal curvatureRoadside or edge hazard ratingDriveway densityPresence of shoulder or centerline rumble stripsPresence of lightingPresence of on-street parking

Intersection FeaturesIntersection skew angleIntersection traffic control deviceNumber of signal heads vs. number of lanesPresence of backplatesPresence of advanced warning signsIntersection located in/near horizontal curvePresence of left-turn or right-turn lanesLeft-turn phasingAllowance of right-turn-on-redPedestrian-related Features

Crosswalk presenceCrossing distanceSignal head typeAdjacent land usesLighting

Limitations to the Site Analysis Approach• 57% of fatal crashes on

rural roads

• Substantial number of fatal crashes on local roads

• Low density on rural and local roadways

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Fatal crash types

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2005 20072006 2008

Factors Influencing Approach

• Data availability• Resources• Established priorities• State/local agency relationship

11Overview

Outcomes of Systemic Safety Planning• Candidate locations for safety investment are identified and

prioritized using selected risk factors

• Selected countermeasures for candidate locations are efficiently bundled into projects and design packages for contract letting

• Effective, low cost countermeasures are applied at the candidate locations to reduce the potential for focus crash types to occur

12Overview

Comprehensive Safety Program• Hot spot safety planning focuses on locations with a history of high

crash frequency• System-based safety planning:

– Is a complementary analytical technique intended to supplement the high crash frequency technique to be more comprehensive and proactive

– Begins with identifying a “problem” based on statewide (or agency-wide) data

– Focuses on one or more low-cost strategies to address the underlying contributing circumstances

– Identifies and prioritizes locations for implementation based on high risk features

– Acknowledges crashes alone are not always sufficient to establish prioritization

Overview13

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Benefits of Systemic Safety Planning

• Proactive program to address fatalities and serious injuries that seemingly occurred at “random” locations

• Greater knowledge regarding severe crashes, including contributing factors and location characteristics– Improve planning, design, and maintenance

practices– Risk management for tort liability

Overview

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Challenges to the Systemic Approach

• Overcoming institutional history• Safety funding• Training/retraining staff to use new methods

and procedures• Accessing information to support

identification of crash risk factors

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Systemic Safety Project Selection Tool

• Step-by-step process to conduct systemic safety analysis and planning

• Method for balancing systemic safety improvements and spot safety improvements

• Mechanism to quantify benefits of systemic safety improvements

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CyclicalPlanningProcess Elem

ent 1

Elem

ent 2

Elemen

t 3

Identify Target CrashTypes & Risk Factors

• Analyze system-wide crash data • Define crash characteristics at the system level

• Identify potential risk factors from characteristics– Roadway and intersection features– Traffic volume– Other i.e. transit stops, land use

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Select focus crash type(s)

Select focus facilities

Identify common

characteristics

Screen & Prioritize Candidate Locations

• Identify network elements analyzed• Verify selected risk factors• Conduct risk assessment• Prioritize roadway facilities– Segments – Horizontal curves– Intersections

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Identifying Systemic Countermeasures

• Initial list of strategies– Low cost– Significant crash reduction

• Assemble initial list– Low cost– Significant crash reduction

• Evaluate & Screen– Effectiveness– Implementation costs– Policies/practices/

experiences

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• Select a few countermeasures for each target crash type

Select Countermeasures

FHWA Proven Countermeasures

http://safety.fhwa.dot.gov/provencountermeasures

Prioritize Projects• Create a decision process – Provides consistency in project development

process– Consider multiple locations for which

countermeasures are appropriate and affordable• Develop safety projects– Apply decision process– Develop specific projects for each candidate site– Document decision process and results

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Identify Funding & Implement Systemic Program

• Guidance for a decision-making process– Not a prescriptive formula

• Options to select funding levels for:– Systemic & site analysis– State system & local system– Segment & intersection projects

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Perform Systemic Program Evaluation

• Structured approach for tracking changes in crashes and defining benefits– Illustrations for presentations to elected/citizens– Economic for B/C calculations

• Program evaluation; not location evaluations• Guidance for interpreting results– Identify if adjustments are needed

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Element 1: 4-Step Project Selection Process

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Review Past Funding Practices• What safety countermeasures were implemented and

where – at what locations and on what system?• What crash types were targeted by these particular

countermeasures?• Were these crash types and mitigation strategies

identified as a priority in your Safety Plan?

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5 Year Crashes - 6,677Funding – $155,946,000

State System - 3,888 – 58%$82,652,000

$155,291,000 - >99%

Rural - 2,998 – 77%$63,642,000

$98,418,000 – 63%

Urban - 890 – 23%$19,010,000

$56,159,000 – 36%

Inters-Related - 667 – 22%$14,001,240

$11,682,000 – 12%

Inters-Related - 346– 39%$7,414,000

$18,495,000 – 33%

Not Inters-Related - 544 – 61%$11,596,100

$37,664,000 – 67%

Not Inters-Related - 2,331 – 78%$49,640,760

$86,735,000 – 88%

Signals – $10,913,000 – 59%Intersection ? – $5,177,000 – 28%

Other – $2,404,000 – 13%

Signal – $3,580,000 – 31%Intersection ? – $1,531,000 – 13%

Other – $6,571,000 – 56%

CrashesProjected Funding

Actual Funding

Road Edge – $23,156,000 – 27%Barrier – $25,085,000 – 29%Other – $31,691,000 – 37%

Segment Improve. – $6,802,000 – 8%

Road Edge – $3,419,000 – 9%Barrier – $15,954,000 – 42%

Other – $5,260,000 – 14%Segment Improve. – $12,955,00 – 34%

Ped Features – $75,000 – >0%

9% Funded – Run Off Road – 40% Crashes42% Funded – Head On – 12% Crashes

14% Funded – Other – 26% Crashes34% Funded – Rear End – 11% Crashes

>0% Funded – Pedestrian – 11% Crashes

27% Funded – Run Off Road – 61% Crashes29% Funded – Head On – 9% Crashes37% Funded – Other – 22% Crashes

8% Funded – Rear End – 8% Crashes

Example: State Crash/Funding Comparison by Urban vs. Rural

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C. Project Type vs. Crash Type-Signals and Head On are generally over funded.-Run Off Road are underfunded.

59% Funded – Angle, Left Turn – 52% Crashes28% Funded – Angle, Left Turn, Rear End – 57% Crashes

13% Funded – Other – 43% Crashes

31% Funded – Angle, Left Turn – 54%13% Funded – Angle, Left Turn, Read End – 59% Crashes

56% Funded – Other – 41% Crashes

B. Urban vs. Rural-Rural state system is under funded; 77% of crashes, 63% of funding.

A. State vs. Local-The state system accounts for 58% of rashes, receives over 99% of the funding

Element 2: Review Past Funding Practices

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Local Case Studies

• Washington State• Kentucky• Indiana• Louisiana

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Thurston County, WA

• FHWA Pilot • Current Approach– Black Spots– Guardrail program– Shoulder widening program– Low Cost Safety Improvements– Sign Maintenance

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Thurston County, WA

• Using crash data• Non-Junction related– Run of the Road• Horizontal curves

– Speed Limit– Shoulder width– AADT < 5,000– Fixed Object Struck

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Thurston County, WA

• Horizontal Curve Risk Factors– Shoulder width– Radius– Speed differential– AADT– Roadside Hazard Rating– Crashes– Intersections

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Kentucky

• Focus Counties– 5 years of crash data– Select routes for RSA’s

• The systemic approach would focus on our crash types – Drop offs, edgelines, horizontal curve signage, tree removal,

vegetation management and delineation for the entire route

– KYTC is working on a program to make HRRR funds available to Counties for horizontal alignment signage• 40% of crashes occur in curves• 20% of our fatalities occur in curves

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Indiana

• Sign replacement (HSIP funding)– Crash reduction factors– Replace all signs• Evaluation 7-16% reduction in crashes in one county

• Past Intersection Focus State– Package treatments

Intersection Safety Implementation Plans (ISIP)

• Began in 2006 as a component of the Focus State initiative

• Focuses on systematic deployment of packages of low-cost countermeasures (e.g. signing, markings, etc.) across numerous locations

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Example Unsignalized Treatment Package

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• Estimated Crash Reduction 30%

• Average cost $6,000/site

• Key to safety effectiveness is widespread deployment

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Questions???

Karen Y. Scurry, P.E.609-637-4207

karen.scurry@dot.gov

http://safety.fhwa.dot.gov

Hillary Isebrands, PE, PhD720-963-3222

hillary.isebrands@dot.gov