1. High Friction Surface Site Selection Analysis Photo from High Friction Surface Roads (http://www.highfrictionroads.com/), High Friction Roads is maintained by pavement engineering firm The Transtec Grouphttp://www.highfrictionroads.com/The Transtec Group Scott Davis, PE Thurston County Washington State EDC Exchange for Local and Tribal Agencies, June 26, 2014

2. June 25, 20142 Study Objectives Repeatable, Repeatable, Repeatable, Repeatable, Repeatable, Repeatable Data Driven Timely

3. June 25, 20143 Where is Thurston County

4. June 25, 20144 Study Methodology http://safety.fhwa.dot.gov/systemic/ Hybrid analysis approach

5. June 25, 20145 Study Steps 1 Network Data Collection 2 Surrogate Selection 3 Facility Type Selection (Systemic Analysis) 4 Candidate Site Selection (Frequency Review) 5 Risk Factor Identification (Systemic Analysis) 6 Risk Factor Analysis (Systemic Analysis) 7 Site Rankings (Systemic Analysis)

6. January 13, 20136 Mobility Database Roadway Video Street View GIS Systems Step 1 – Network Data Collection Crash Data

7. June 25, 20147 Step 2 - Surrogate Selection 2006-2010 Fatal & Serious Collisions (xx) = Total Fatal & Serious Crashes % = percent skidding related crashes Skidding/Out-of-Control Driver Actions & Icy Roads

8. Step 3 – Facility Type Selection Wet, Icy and Skidding Crash Review 90% of severe crashes occurred on arterial & collector roads Arterial & collector roads represent about 33% of network length June 25, 20148 Federal Functional Classification Map

9. Step 4 – Candidate Site Selection 67 Roads Reviewed 75 Candidate Sites Identified Site Facts 52 are on horizontal curves 20 are on vertical grades 6 are on curves identified in Horizontal Curve Systemic Analysis COUNTY ROAD NAME MILE POST MOST SEVERE INJURY TYPE JOHNSON PT RD0No Injury JOHNSON PT RD0.9No Injury JOHNSON PT RD0.9No Injury JOHNSON PT RD0.9Dead at Scene JOHNSON PT RD0.9Possible Injury JOHNSON PT RD0.9No Injury JOHNSON PT RD0.902Serious Injury JOHNSON PT RD0.909No Injury JOHNSON PT RD0.919Unknown JOHNSON PT RD1No Injury JOHNSON PT RD1.665Possible Injury JOHNSON PT RD2.37Possible Injury JOHNSON PT RD3.184No Injury JOHNSON PT RD3.388No Injury June 25, 20149

10. Step 5 – Risk Factor Identification Speed Limit Roadway Classification Intersections Roadway Geometry Traffic Volume Traffic Control Type Shoulder Type Shoulder Width Severe Crashes 20 Intersection Focus List 20 Systemic Curve Focus List June 25, 201410

11. January 13, 201311 Pivot Tables Charts MS Excel Macros Step 5 – Risk Factor Analysis Use Speed Limit Chart

12. Paved Shoulders of 4’ in width are over- represented Paved Shoulders of 8’ in width also have a small over- representation. June 25, 201412 Step 6 – Risk Factor Analysis Use Speed Limit Chart Speed Limit (on-system roads) vs. Skidding/Out of Control Crashes Speed Limit (on-system roads) vs. Skidding/Out of Control Crashes

13. Served as Guide Only June 25, 201413 Simple Scoring System Higher Confidence in results resulted in highest score Lower Confidence in results resulted in lowest score Step 6 – Risk Factor Analysis

14. June 25, 201414 Step 6 – Risk Factor Analysis 1 Point Factors Posted Speed Limit Traffic Volume Horizontal Curve

15. June 25, 201415 Step 6 – Risk Factor Analysis 1/2 Point Factors Shoulder Type and Width Traffic Volume Horizontal Curve with on a grade

16. Road Name Length (mi.) Skidding Crashes 5 year rate Severe Crashes Risk Score OLD HWY 99 SW0.880.82No4 RESERVATION RD SE0.37560.46No4 VAIL LOOP RD SE0.2131.93Yes3.5 Note: Crash totals and rates based on skidding/out of control crash types June 25, 201416 Step 7 – Site Rankings Reservation Rd SE Old Hwy 99 SE Vail Lp Rd SE

17. June 25, 201417 Wrap Up Top 10 List 1Old Hwy 99 SW 2Reservation Rd 3Vail Loop Rd SE 4Bald Hill Rd 5Morris Rd 6Alyger Rd 7Johnson Pt Rd 8Yelm Hwy 962 nd Ave 1 st Planned High Friction Installation