Module
1
Introduction:
Overview of
Roadway Safety
Management
Safety Analysis in a Data-limited, Local
Agency Environment:
July 22, 2013 - Boise, Idaho
1
Introduction:
Learning Objectives
Define nominal and substantive safety
 Discuss different approaches to safety
projects
 Define key steps of the roadway safety
management process
 Introduce safety analysis tools

2
Introduction
“Road safety management is in
transition. The transition is from
action based on experience,
intuition, judgment, and tradition,
to action based on empirical
evidence, science, and
technology…”
Ezra Hauer (May 2005)
3
How do you define Safety?

Definitions of Safety

Personal – Do I feel safe?


Based on personal experiences
Level of comfort or discomfort
Engineer – design meets standards and/or
crash frequency below threshold
 Legislation – Fatal and injury crashes

4
Nominal vs Substantive Safety
11-ft lanes
Which model more closely
resembles what stakeholders
are likely thinking?
12-ft lanes
5
A facility may be “nominally safe” but have a lower
actual safety performance (i.e. substantive safety)
6
Different approaches to safety
Opportunities
During
Project
Scoping and
Design
Traditional
Practice
Site-specific
projects
Low Cost
Improvement
Opportunities
Benefits
through
Systematic
Improvements
Systemic approaches
Thinking out
of the Box
Opportunities to
Optimize Safety
Benefits
7
Different approaches to safety
Data-driven and science-based
Site-specific
Systemic
Evaluate the safety
performance of a
particular site
We know a low cost
countermeasure
that works, e.g
rumble strips
Identify target
crashes
Identify, evaluate
and implement
countermeasures
Identify sites with
characteristics
appropriate for the
low cost treatment
Implement the
systemic treatment
(always low cost)
8
Common data elements
Crash
data
• Crash location, crash severity, roadway conditions
(lighting conditions, weather), date and time of the crash,
users involved, vehicles involved, driver actions and
condition (alcohol, drugs), and contributing circumstances
Roadway
data
• Number and widths of lanes, shoulder widths and types,
roadway alignment (straight or curved), intersection
configuration (number and types of lanes) and traffic
control
Exposure
data
• Traffic Volumes
9
Roadway
Safety
Management
Process
HSM Part B
(Chapters 4 – 9)
Chapter 4
Network Screening
Chapter 5
Chapter 6
Diagnosis &
Countermeasure
Selection
Chapter 7
Chapter 8
Economic Appraisal
& Prioritization
Chapter 9
Safety Effectiveness
Evaluation
Network Screening
5 key steps
• Establish
Focus
STEP 1.
STEP 2.
• Identify
Reference
Populations
• Select
Performance
Measures
STEP 3.
STEP 4.
• Select
Screening
Methods
• Screen and
Evaluate
Results
STEP 5.
11
Site diagnosis process



STEP 1: Review safety data
STEP 2: Assess supporting documentation
STEP 3: Assess field conditions
Desired Outcomes
 Identify contributing circumstances to crashes at
the site
 Understand site conditions
 Identify crash patterns
 Gain insight on countermeasure selection
12
Selecting Countermeasures

Key Steps
Identify
contributing
factors to
crashes
Select potential
countermeasures
or treatments
Apply
countermeasures
13
Economic Appraisal
Key Steps:
Identify Data Needs
 Assess Expected Project Benefits
 Estimate Project Costs
 Perform Economic Evaluation
 Consider Non-Monetary Impacts

5-14
Project Prioritization
Is the alternative economically justified?
Prioritization Methods
 Ranking by economic effectiveness
 Incremental benefit-cost analysis
 Optimization methods
Remember though! include non-monetary
considerations
5-15
Implement and evaluate the
effectiveness of countermeasures
Implement countermeasures
 Evaluate countermeasures – how well is it

working for us? Should we do more of these projects?
Are there ways to improve?

We can evaluate



A single project at a specific location, or
A group of similar projects, or
A group of projects.
16
Potential resources & tools
FHWA CMF Clearinghouse
usRAP
AASHTO
Highway Safety
Manual
FHWA
Systemic
Tool
17
Highway Safety Manual
Vol. 1 (Part A)
Introduction
Human Factors
Fundamentals
Vol. 2 (Part C)
Predictive
Methods
Vol 1. (Part B)
Roadway Safety
Management
Process
Vol 3. (Part D)
Crash
Modification
Factors (CMFs)
www.cmfclearinghouse.org
2-19
FHWA Systemic Safety Project
Selection Tool
1. Identify Target Crash
Types and Sites
2. Screen and Prioritize
Candidate Locations
3. Select Countermeasures
4. Prioritize Projects
5. Identify Funding Source
and Implement Systemic
Program
6. Evaluate Systemic
Program
20
Summary
Substantive safety is key to informed and
defensible decisions
 Approaches in roadway safety
management allows for implementation at
all levels of data availability
 Resources and tools are available to
support activities

21
End
Module 1
Questions?
22