Overview of the New Highway Safety Manual

1. Overview of the New Highway Safety Manual Ray Krammes, FHWA May 12, 2009 Columbia, Missouri Missouri Traffic & Safety Conference

2. Presentation Summary • What is the HSM? • Why is the HSM needed? • What is covered by the HSM? • Who should use the HSM? • When will the HSM be available? • What support will be available to implement the HSM? • Where can one find more about the HSM?

3. Overview of the new HSM WHAT IS THE HSM?

4. WHAT IS THE HSM?

5. The Vision of the HSM - A Document Akin To the HCM 1 2 3

6. What the HSM is NOT vs • The HSM does not set requirements or mandates • The HSM isnot a best practice document for design or operations. • The HSM contains no warrants or standards and does not supersede other publications that do.

7. Overview of the new HSM WHY IS THE HSM NEEDED?

8. Is This Road “Safe” or “Unsafe”? What does safety really mean?

9. Highway Safety Has Two Dimensions Examined in reference to compliance with standards, warrants, guidelines and sanctioned design procedures The expected or actual crash frequency and severity for a highway or roadway *Ezra Hauer, ITE Traffic Safety Toolbox Introduction, 1999

10. Substantive Safety May Vary When Nominal Safety Does Not Alternative 1 Existing Conditions Alternative 3 Alternative 2

11. Substantive Safety Best measured in terms of expected (long-term) average crash frequency Ways to estimate: Crash data Predictive methods Safety Performance Functions (SPFs) Accident Modification Factors/Functions (AMFs) Combination (Empirical Bayes)

17. Overview of the new HSM WHAT IS COVERED BY THE HSM?

18. Outline of the HSM

19. PART AIntroduction, Human Factors, & Fundamentals

20. Npredicted = Nspfx*(AMF1x*AMF2x*... *AMFyx )*Cx Where, Npredicted= predicted average crash frequency for a specific year for site type x; Nspf x= predicted average crash frequency determined for base conditions of the SPF developed for site type x; AMFyx= Accident Modification Factors specific to SPF for site type x; Cx= calibration factor to adjust SPF for local conditions for site type x.

21. Part BRoadway Safety Management Process 6 7 9 8 4

22. Chapter 4. Network Screening

23. PART CPREDICTIVE METHODS • Calibration • Combining predicted with observed crashes Special Part C Common Procedures

24. Exhibit 10-5: Graphical Form of SPF for Rural Two-Lane Two-Way Roadway Segments(Equation 10-6)

25. Exhibit 10-9: Graphical Representation of the SPF for Four-leg STOP controlled (4ST) Intersections(Equation 10-9)

26. Part DAccident Modification Factors

27. Exhibit 10-16: AMF for Shoulder Width on Roadway Segments (AMFwra)

28. Overview of the new HSM WHO SHOULD USE THE HSM?

29. Who Should Use the HSM?

30. Overview of the new HSM WHEN WILL THE HSM BE AVAILABLE?

31. Implementation Schedule

32. Overview of the new HSM WHAT SUPPORT WILL BE AVAILABLE TO IMPLEMENT THE HSM?

33. Training & Outreach Activities • Sept – Nov 2009 • Conduct two or three multi-state pilot courses • TRB 2010 Annual Meeting • One-day workshop • Training materials, including “Train-the-trainer” available upon HSM release

34. FHWA Tools Supporting HSM Use

35. WHERE CAN ONE FIND MORE ABOUT THE HSM? Overview of the new HSM

36. http://www.highwaysafetymanual.org

37. The End Questions?