Best Practices for Systemic Safety Planning

TxDOT Short CourseBest Practices for Systemic Safety Planning

October 2020

FHWA Resource Center 1

Best Practices for Systemic Safety Planning

Hillary Isebrands, PE, PhDFHWA, Resource Center, Safety and Design

National Technical Service Team720-545-4367

Glen Rose Hwy, Granbury, TX

Texas SHSP (2017-2022)

2

Emphasis Areas• Distracted driving• Impaired driving• Intersection safety• Older road users• Pedestrian safety• Roadway and lane

departures• Speeding

3,218, 8%

8,301, 21%

5,467, 14%

3,335, 8%3,490, 9%

10,652, 27%

5,360, 13%

TX Fatalities (2010‐2016)

Distracted Driving Impaired Driving

Intersections Older Road Users

Pedestrians Roadway & Lane Departures

Speeding


October 2020


Poll 1

• How many fatalities are in your District, Jurisdiction or Community each year?a) 0

b) Between 1 ‐ 50

c) Between 51 to 100

d) Between 101 – 500

e) Between 501 – 1,000

f) >1,000

g) I do not know

TxDOT - Safety Improvement Program Guidelines – June 2020

http://ftp.dot.state.tx.us/pub/txdot‐info/trf/hsip/hsip‐guidance‐june‐2020.pdf


October 2020


Terminology

• Site‐Specific approach (aka hot‐spot or high crash location):• deploying site‐specific improvements at locations with the highest frequency of crashes• E.g. installing a roundabout at a intersection experiencing a large number of severe crashes

• Systematic Approach (aka system wide or policy‐based):• deploy countermeasures on an entire system

• E.g. installing edgeline pavement markings on all paved routes

• Systemic approach: • deploy cost‐effective countermeasures at locations with the greatest risk

• E.g. installing chevrons and enhanced pavement markings at curves with radii between 500‐1000 ft


October 2020


Definition: Systemic Safety

The term "systemic safety improvement" means an improvement that is widely implemented based on high‐risk roadway features that are correlated with particular crash types, rather than crash frequency.‐‐ 23 USC 148 (a)(12) Systemic safety improvement

Source: FHWA

Systemic Safety Explanation Video

https://youtu.be/iGlFGvxmoiQ

https://safety.fhwa.dot.gov/rsdp/ddsa_resources/ddsa_systemic_analysis.pdf


October 2020


Benefits of a Systemic Safety Planning Approach

• Proactive program to address likelihood of severe crashes• Addresses 'random' nature of severe crashes

• Greater knowledge of severe crashes• Contributing factors and location characteristics• Improve planning, design, and maintenance practices

• Risk management for tort liability

• Focus on low cost proven safety countermeasures

Random Nature of Crashes

20122013201420152016


October 2020


Safety Data and Risks to Consider….

Crash

Traffic Volume

MaintenanceLogs

RoadSafetyAudits

Enforcement

Roadway

SafetyData

11

Source: FHWA

Source: FHWA


October 2020


FHWA’s Systemic Safety Tool

https://safety.fhwa.dot.gov/systemic/fhwasa13019/sspst.pdfhttps://safety.fhwa.dot.gov/systemic/pdf/fhwasa17002.pdf

FHWA Local Road Safety Plan – Do it Yourself Websitehttps://safety.fhwa.dot.gov/LRSPDIY/


October 2020


Systemic Safety Process

1. Systemic Safety Planning Process

2. Funding‐ Program and Implementation

3. Evaluate Effectiveness

3 Elements:

Step 1

Step 2

Step 3

Step 4

Tasks 1 & 2: Identify Focus Crash Types and Facility Types

16


October 2020


Identify Focus Crash Types & Facilities

Fatal and Severe Injury Crashes (5 Years)Percent by Jurisdiction

Emphasis AreaStatewide114,592 mi

State15,486 mi

County19,938 mi

City, Town, Village76,735 mi

Total Fatal/Serious Injury 100% 63,443 31% 19,819 10% 6,572 45% 28,597

Pedestrian 19% 11,786 9% 1,860 6% 421 28% 8,122

Bicycle 5% 3,390 3% 518 3% 187 8% 2,414

Heavy Vehicle 5% 3,123 6% 1,266 4% 234 4% 1,051

Road Departure 26% 16,668 30% 5,985 44% 2,892 18% 5,128

Intersection 41% 25,791 25% 5,033 30% 1,957 64% 18,270

Head‐on and Sideswipe 5% 3,071 7% 1,439 7% 490 3% 887

18

WA Crash Data Comparison for Risks


October 2020


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Crash Tree Diagrams – Statewide/Rural

Crash Tree Diagram - Palm Beach County, FL


October 2020


Crash Tree Combinations

Primary

• State / local

• Rural / urban

• Segment / intersection

• Segment type• Freeway, multilane, two‐lane, one‐way

• Intersection control• Signalized

• Unsignalized

• Uncontrolled

Secondary

• Tangent / curve

• High‐speed / low‐speed

• Street lighting

• District or regions

• Traffic volume

• Lane width

• Shoulder type/width

• Alignment

• Land use

FHWA STEP - Pedestrian Countermeasure Matrix

https://safety.fhwa.dot.gov/ped_bike/step/docs/STEP_Guide_for_Improving_Ped_Safety_at_Unsig_Loc_3‐2018_07_17‐508compliant.pdf


October 2020


Crash Data Summary Template & Crash Tree Maker v 2.0 – Coming Soon

Poll 2

Have you used a Crash Decision Tree or Countermeasure Decision Tree before when making decisions for prioritization of projects or countermeasures?

a) Yes

b) No

c) No, but I would like to

d) I do not know


October 2020


Task 3: Identify & Evaluate Risk Factors

25

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.

26

Source: FHWA


October 2020


Potential Risk Factors

• Number of lanes

• Lane width

• Shoulder width / type

• Median width / type

• Driveway density

• Roadside

• Horizontal curvature• Superelevation• Delineation• Advance warning• Speed differential• Visual trap

2727

• Traffic control device

• Left‐turn or right‐turn lanes

• Skew angle

• Advance warning signs

• Located in or near horizontal curve

• Type of development (e.g., commercial)

• Signals• Left‐turn phasing• Number of signal heads vs. number of lanes

• Backplates• Right‐turn‐on‐red• Overhead versus pedestal mounted

Roadway Dep

arture

Intersections

Potential Risk Factors - Pedestrians

• Ped volumes

• Controlled or uncontrolled• Type (if controlled)

• Marked or unmarked

• Pedestrian signal/type• Sidewalk presence• Lighting• Bus Stops• Adjacent land use type

• Schools• commercial, or alcohol establishments

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Pedestrians


October 2020


Examples of Potential Risk Factors

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

Percent

Curve Radius (ft)

Horizontal Curve Radius

Percent of Severe Crashes Percent of Severe Lane Departure Crashes Percent of Curves 29

62% of Severe Crashes occurred on 41% of the Curves

Examples of Potential Risk Factors

Edge Clearance 1

Edge Clearance 2

Edge Clearance 3

30

17%(45)

64%(170)

19%(52)

24%(54)

45%(102)

31%(70)

22%(8)

42%(15) 36%

(13)

Edge Clearance 1 Edge Clearance 2 Edge Clearance 3

Percent of Curve Inventory (267)Percent Injury (226)Percent Severe (36)


October 2020


Qualitative Approach to Risk Factors

Use qualitative ratings when needed:

• Traffic volume: high, medium, or low

• Curves: sharp or flat

• Shoulder width: wide, narrow or none

• Lane width: typical or narrow

• Roadside: good, fair, poor

Poll 3

List some of your biggest risk factors in your jurisdiction or community (select all that apply)

a) Curves

b) Intersections

c) Number of Lanes (peds)

d) 2 lane rural

e) Other

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October 2020


Systemic Safety Planning Process

Step 1

Step 2

Step 3

Step 4

Example - Simple Risk Factor Scoring


October 2020



Step 1

Step 2

Step 3

Step 4

36http://safety.fhwa.dot.gov/provencountermeasures


October 2020



Step 1

Step 2

Step 3

Step 4

Example of Balancing Programs

Site‐Specific

Systemic

https://safety.fhwa.dot.gov/hsip/planning.cfm


October 2020


State DOT Examples of Systemic Benefit Cost Requirements

• Indiana• No Benefit Cost required for Approved Systemic Safety Improvements

• California• A minimum Benefit Cost Ratio may be established in each cycle of the HSIP call for projects. The project selection results from the previous HSIP cycles indicates that the cut‐off BCR can be well above 1.0.

• Minnesota

Summary

• How Healthy is your Road System?

• How can Systemic Safety enhance safety on your roadways?

• Are you deploying proven safety countermeasures on your projects?

• What are some of the Systemic Safety Planning and Analysisresources?


October 2020


Contact Information

• Heather L. Lott, P.E.Traffic Engineering Section Director, Traffic Safety Division, TxDOT512‐416‐[email protected]

• Hillary Isebrands, PE, PhDSenior Safety Engineer/Team LeaderFHWA – Resource Center720‐545‐[email protected]

• Stephen (Steve) J. Ratke, P.E., RSP1Safety and Traffic Operations SpecialistFHWA ‐ Texas Division512‐536‐5924 – [email protected]

• Karen Scurry, PEFHWA Office of Safety 202‐897‐[email protected]

Thank You!

Have a Safe Day!

Documents

Best Practices for Systemic Safety Planning