Murray Boulevard and Farmington Road Intersection

1. Murray Boulevard and Farmington Road Intersection CEE 550 Transportation Safety Analysis Sirisha Kothuri Wei Feng Ping Guo Meead Saberi

2. Outline • Introduction • Site Description • Crash Data Analysis • Literature Review • Countermeasures • Cost/Benefit Analysis • Recommendations

3. Introduction • Murray Boulevard • 2 lane undivided • Runs N-S • Farmington Road • 2 lane undivided • Runs E-W • Intersection • City of Beaverton • 4-leg signalized • Slight skew • High Volume Map of Intersection

4. MurrayBlvd Apt Off Farmington Road 7-Eleven Apt Site Description - I Aerial View of the Intersection

5. Site Description - II Illumination at Intersection Signal at Intersection Barrier at Intersection Pavement Markings at Intersection

6. Site Description - III Speed Limit Sign on Farmington Speed Limit Sign on Murray Driveways near Intersection School Zone Signs

7. Site Description - IV Heavy Vehicles Queue Spillover to Adjacent Intersection

8. Volume Source: City of Beaverton

9. Crash Data Analysis Oregon Transportation Safety Data Archive (ortsda) • Crash File • Crashes for 4 Years (2003 -2006) at intersection • Vehicle File • Information about vehicles involved in crashes at intersection • Participant File • Information about drivers involved in crashes at intersection Crash Patterns at the Intersection • Time of Day • Type of Crash • Severity • Weather • Light Conditions • Driver Characteristics • Residence Status • Gender • Age

10. Time of Day

11. Type of Crash

12. Crash Severity

13. Crash Cause

14. Murray Blvd Farmington Rd Collision Diagram

15. Rear End Crashes Most common type at signalized intersections Account for one-third of all reported crashes in US Mostly PDO, sometimes severe injuries and fatalities occur Causes Driver Behavior – Inattentive driving, smaller headways Driver Age and Gender Heavy Traffic Volumes Dilemma Zone Literature Review

16. Dilemma (Indecision) Zone Source: Heng Wei, Characterize Dynamic Dilemma Zone and Minimize its Effect at Signalized Intersections, Ohio Transportation Consortium (OTC), 2008

17. Dilemma (Indecision) Zone

18. Countermeasures • Reduce speed limit on approaches to • 35 mph on Murray Blvd • 30 on Farmington Road • Pros • Reduction in all types of crashes • Cons • Increase in delay • Diversion of vehicles to other streets

19. Countermeasures • 2. Advance Signal • Warning Signs • Murray Blvd & Farmington Rd • Pros • Reduction in Rear End Crashes • Low cost • Easy Implementation • Cons • Need space?

20. Countermeasures • Improve Signal Timing • Optimize to ITE Standards • Pros • Reduces Rear End PDO crashes • Cons • Increases Fatal and Injury crashes?!

21. Countermeasures • Coordinated Signals • Coordinate adjacent intersections • Pros • Allows progression of vehicles • Reduces all types of crashes • Cons • Hard to implement

22. Select Countermeasures For each countermeasure, extract CRF Calculate reduction in crashes Calculate annual benefits and costs Assume discount rate of 4% Calculate NPV = NPVB – NPVC Rank countermeasures in decreasing order of NPV Cost Benefit Analysis

23. Cost Benefit Analysis Cost of All Crashes at Intersection (4 years)

24. Cost Benefit Analysis • Reduce vehicle’s approach speed limit $76,875 $44,688 $43,062 $42,937 $10,250

25. Cost Benefit Analysis 2. Advance Signal Warning Signs $121,770 $62,010 $40,950

26. Conclusions & Recommendations • Rear-end crashes are common at signalized intersections. • Typical causes • Driver Behavior • Driver Age & Gender • Heavy Traffic Volumes • Dilemma Zone • Countermeasures Ranking Based on B/C Analysis • Install Advance Signal Warning Signs • Reduce vehicle’s approach speed limit • Signal Coordination

27. Dr. Chris Monsere, PSU Jabra Khasho, City of Beaverton Baotu Ho, City of Beaverton Acknowledgements