HSM Use and Training Karen K. Dixon, Ph.D., P.E. Oregon State University

Presentation Summary

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

What is the HSM? Provide Information Tools To facilitate explicit safety considerations for: Planning DesignOperationsMaintenance through Synthesis of validated highway research Adapted & integrated to practice Analytical tools for predicting impact on road safety

The Vision of the HSM - A Document Akin To the HCM Definitive; represents quantitative ‘state- of-the-art’ information Widely accepted within professional practice of transportation engineering Science-based; updated regularly to reflect research1 2 3

W HAT THE HSM IS NOT The HSM does not set requirements or mandates The HSM is not a best practice document for design or operations. The HSM contains no warrants or standards and does not supersede other publications that do. vs

The HSM does not establish a legal standard of care nor does it create a duty to the public.

II. W HY D O W E N EED THE HSM? Overview of the new HSM

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

Nominal Safety Substantive Safety 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 Highway Safety Has Two Dimensions *Ezra Hauer, ITE Traffic Safety Toolbox Introduction, 1999

CRASH RISK DESIGN DIMENSION Lane Width, Radius of Curve, Stopping Sight Distance, etc. CRASH RISK DESIGN DIMENSION Lane Width, Radius of Curve, Stopping Sight Distance, etc. Unlike Nominal Safety, Substantive Safety is a Continuum Substantive Safety Nominal Safety

Nominal Safety versus Substantive Safety CRASH RISK DESIGN DIMENSION Lane Width, Radius of Curve, Stopping Sight Distance, etc. Low Nominal Low Substantive Low Nominal Low Substantive Low Nominal High Substantive Low Nominal High Substantive High Nominal Low Substantive High Nominal Low Substantive High Nominal High Substantive High Nominal High Substantive

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

We’re Interested in Other Impacts for Project Level Decisions – What About Substantive Safety? Safety Environmental Traffic Right-of-Way Costs Impacts Impacts Operations Traffic Noise Model 1.0 CAL3QHC Mobile 5a 3-D Visualization CITYGREEN HCM CORSIM PASSER TRANSYT7F VISSIM Construction Plans Cost Models Real estate appraisals DOT databases Design Criteria (nominal safety) More quantitative Greater weight The HSM

The HSM Contains Best Science & Research Synthesis of previous research New research commissioned by AASHTO and FHWA

III. HOW WAS THE HSM DEVELOPED? Overview of the new HSM

The HSM – A Ten-year Research And Development Effort TRB Annual meeting Absence & need to estimate safety impacts TRB December Workshop TRB Joint Subcommittee for the Development of a HSM Members of sponsoring committees AASHTO, FHWA, ITE TRB Task Force for the Develop- ment of a HSM AASHTO HSM TF 1 st Edition (projected) 2 nd Edition Future Research, research and more research

Significant Effort & Professional Support Produced the HSM Joint Subcommittee sponsored by 7 TRB committees Thousands of hours of volunteer effort Research program funded by NCHRP, AASHTO & FHWA

NCHRP Project 17-18(04) Development of a HSM - Draft Table of Contents for the HSM. NCHRP Project Crash Reduction Factors for Traffic Engineering and ITS Improvements NCHRP Project Development of Models for Prediction of Expected Safety Performance for Urban and Suburban Arterials NCHRP Project Prepare Parts I and II of the HSM NCHRP Project Safety Prediction Models for Rural Multilane Highways for Use in the HSM NCHRP Project Prepare Parts IV and V of the HSM NCHRP Project Production of the First Edition of the HSM NCHRP Project Pedestrian Predictive Crash Methodology for Urban and Suburban Arterials NCHRP Project HSM Implementation and Training Materials Research Path to the HSM v.1

IV. W HAT IS C OVERED BY THE HSM? Overview of the new HSM

Outline of the HSM Part A Introduction, Human Factors, and Fundamentals Part B Roadway Safety Management Process Part C Predictive Method Part D Accident Modification Factors

PART B: Roadway Safety Management Process SafetyAnalyst org/ PART C: Predictive Methods IHSDM y/ ihsdm/ihsdm.htm PART D: Accident Modification Factors FHWA CRF/AMF Clearinghouse

PART A INTRODUCTION, HUMAN FACTORS, & FUNDAMENTALS Introduction and Overview Chapter 1 Human Factors Chapter 2 Fundamentals Chapter 3

Part B Roadway Safety Management Process Network Screening Diagnosis Countermeasure Selection Economic Appraisal Prioritization of Improvement Projects Safety Effectiveness Evaluation

Part C Predictive Method Two-Lane Rural Roads Urban/ Suburban Arterial Highways Rural Multilane Highways Methodology Applications Safety issues not explicitly addressed by the methodology Example problems References Special Part C Common Procedures Calibration Combining predicted with observed crashes

Definition of HSM Terms Safety Performance Function (SPF) – a regression equation used for estimating the predicted crash frequency at a site for a given “base condition” Accident Modification Factor (AMF) – used to adjust the “base condition” in the SPF to specific site characteristics Calibration Factor (C) – adjusts average crash frequencies calculated from the SPF to local site conditions

Predicting Crashes – Defining Roadway Segments and Intersections

HSM Regional SPF Calibration Step 5 – Compute calibration factors for use in Part C predictive model Step 1 – Identify facility types of interest Step 2 – Select sites for calibration of each facility type Step 3 – Obtain data for each facility type applicable to the calibration period Step 4 – Apply the appropriate Part C predictive model to estimate expected crash frequency for each site during the calibration period

Part D Accident Modification Factors Roadway Segments CHAPTER 13 Intersections CHAPTER 14 Interchanges CHAPTER 15 Special Facilities and Geometric Situations CHAPTER 16 Road Networks CHAPTER 17

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

Who Should Use the HSM? System Planning Project Planning Preliminary Design, Final Design, & Construction Operations & Maintenance

Assess the system needs & identify projects/studies Program projects Evaluate system-wide safety effects of programs System Planning Project Planning Preliminary Design, Final Design, and Construction Operations and Maintenance

Define problem(s) and assist in scoping Identify potential solutions Assess or evaluate multiple alternatives and expected quantitative safety effects Aid in identification of a preferred alternative System Planning Project Planning Preliminary Design, Final Design, and Construction Operations and Maintenance

Evaluate safety of alternative design approaches Assist in review & documentation of design exceptions, variances and waivers Inform decisions on construction staging, work approaches, etc. System Planning Project Planning Preliminary Design, Final Design, and Construction Operations and Maintenance

Monitor operations to maintain balance among safety, mobility and access. Evaluate the effectiveness of implemented improvements System Planning Project Planning Preliminary Design, Final Design, and Construction Operations & Maintenance

VI. W HEN W ILL THE HSM BE A VAILABLE ? Overview of the new HSM

Implementation Schedule Now through July 31, 2009: Review & balloting by AASHTO ‘s Subcommittee of Traffic Engineering, Standing Committee on Highway Traffic Safety, and Subcommittee on Design Sept 1 st to 30 th, 2009 – Ballot by AASHTO’s Standing Committee on Highways & Standing Committee on Highway Traffic Safety Expected Release Date: Early 2010

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

VII. W HERE C AN O NE F IND M ORE I NFORMATION A BOUT THE HSM? Overview of the new HSM

DATA NEEDS GUIDE

Key Contacts AASHTO – Ken Kobetsky: (202) – Jim McDonnell: (202) – Joel McCarroll: (202) AASHTO JOINT TASK COMMITTEE FOR THE HSM – Don Vaughn, ALDOT, (334)

Key Contacts TRB/ NCHRP – Rick Pain: (202) – Chuck Niessner: (202) TRB HSM TF: Development of a Highway Safety Manual – John Milton, (360) TRB HSM TF: User Liaison – Geni Bahar (User Liaison Subcommittee of the TRB HSM Task Force): (416) TRAINING – Karen Dixon (PI of NCHRP Project 17-38): (541)

The End Questions?