Transcript presentation file - ITS ITE at UMD

ENCE688F and
Highway Safety Manual
Dr. Mohamadreza Banihashemi
Senior Transportation Research Engineer II
GENEX Systems
University of Maryland Seminar
November 2014
Slide 1
Seminar Breakdown
ENCE688F: Highway Safety Fundamentals
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History and Trends
Definitions and Concepts
Crash Studies and Crash Data
Crash Prediction Models
Major National Highway Safety Programs, HSM and SHRP2
Software Packages, Databases (i.e., SHRP2 RID)
IHSDM, a Course Project
Implementation of the HSM in the IHSDM Software
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Slide 2
Highway Safety Manual (HSM) Overview
IHSDM Overview
Relationship between HSM and IHSDM
Use of IHSDM / HSM in Developing a Sustainable Highway
System
Questions / Discussion.
ENCE 688F:
Highway Safety Fundamentals
A Graduate Course Focusing on
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Slide 3
Highway Safety History and Trends
Definitions and Concepts
Crash Studies and Crash Data
Highway Safety Quantitative Evaluation
Crash Prediction Models
Major National Highway Safety Programs
Software Packages, Databases (i.e.,
SHRP2 RID)
Course Project (IHSDM Software).
This is not
A Highways Safety Manual Course, or
An IHSDM Software Course, or
A SHRP2 Safety Program Training.
This is a Course in Highway Safety
Fundamentals including many components
of the above!!
Slide 4
History and Trends
Organizations:
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Slide 5
Federal Highway Administration (FHWA)
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Federal-Aid Program
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MUTCD
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Software/Website Development
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Actively Supporting HSM
Transportation Research Board (TRB)
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Highway Safety Manual (HSM) 1st Edition
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SHRP2
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Toward HSM 2nd Edition
American Association of State Highway and
Transportation Officials (AASHTO)
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Highway Safety Manual (HSM)
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Some Other Programs
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HSM Publication and Support.
History and Trends -Continue
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Slide 6
Highway Crash Fatality Trend
The First Period of Rising Automobile Use in the US
First National Conferences on Street and Highway
Safety
Balanced Design for Safety, Design Speed Concept
Early Studies on the Effect of Highway Geometry
on Safety
An Erroneous Study Result: “The Accident Prone
Driver”
National Programs of Research and Development.
Definitions and Concepts
Introducing main highway safety
concepts and measures:
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Design Speed Concept and its Deficiencies
Nominal Safety Measures
Substantive Safety Measures
Surrogate Safety Measures (Diagnostic
Safety)
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Slide 7
Operating Speed
Near Crash.
Definitions and Concepts -Continue
Major Factors Known as Causes of
Crashes
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Human
Vehicle
Highway
Environment
Cause and Effect vs. Correlation
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Slide 8
Older drivers and crash severity
Speed and crash severity.
Crash Characteristics
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Highway Purpose and Functional
Classification
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Mobility vs. Access
Functional Classification Effects on
Highway Design
 Design Factors Affecting Safety the
Most
 Some National Crash Characteristics
and Trends.
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Slide 9
Highway Characteristics and Safety
Major Highway Characteristics by
Functional Class
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Slide 10
Traffic Volume
Traffic Control
Highway Geometry
Auxiliary Lanes
Roadside
Lighting
Speed Enforcement.
Intersection/interchange Characteristics and Safety
Major Intersection Characteristics by
Functional Class
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Slide 11
Volume
Traffic Control
Intersection Layout/Skew Angle
Interchange Configuration
Turn Lanes/Islands
Lighting.
Roundabout, A New Type of Intersection
Traffic Circles (Rotaries)
 Neighborhood Traffic Circles
 Modern Roundabouts
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Yield control
Channelization
Geometric curvature to limit the speed
Safety Effect of Replacing
Intersections with Roundabouts
 New Researches on Roundabouts.
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Slide 12
Types of Crash Data and Crash Studies
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Observational vs. Experimental Data
Longitudinal vs. Cross Sectional Data
Panel Data
Before-and-After Data
Some Sources for Inconsistencies and
Biases
Basic Types of Highway Safety Studies
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Slide 13
Naïve and Improved Before-After Studies
Cross Sectional Studies
Empirical Bayes Studies.
Crash Data, Sources
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National highway Traffic Safety
Administration (NHTSA)
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Slide 14
National Automotive Sampling System (NASS)
Fatality Analysis Reporting System (FARS)
Crashworthiness Data System (CDS)
General Estimates System (GES)
Highway Safety Information System
(HSIS)
Other State Data
GIS Data
NDS Data Collected in SHRP2 Project.
Common Types of Crash Prediction Models
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Main Assumptions
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Most Common Models
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Negative Binomial
Linear and Non-Linear Regression
Models with Crash Modification Factors
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Crash count obeys Poisson probability law
Estimates of crashes follow Gamma distribution
Safety Performance Functions
Crash Modification Factors
Empirical Bayes Process.
Highway Safety Manual (HSM)
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Part A – Introduction & Fundamentals
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Part B – Safety Process
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Slide 16
Chapter 1 Introduction and Overview
Chapter 2 Human Factors in Road Safety
Chapter 3 Fundamentals
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
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Network Screening
Diagnosis
Selection of Countermeasures
Economic Appraisal
Prioritization of Improvement Projects
Safety Effectiveness Evaluation.
More on Highway Safety Manual (HSM)
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Slide 17
Part C – Predictive Methods
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Chapter 10 Rural, Two-Lane Roads
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Chapter 11 Rural, Multilane Highways
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Chapter 12 Urban/Suburban Arterial Highways
Part D – Accident Modification Factors
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Chapter 13 Roadway Segments
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Chapter 14 Intersections
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Chapter 15 Interchanges
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Chapter 16 Special Facilities & Geometric Situations
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Chapter 17 Road Networks
Part C – HSM Supplement
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Chapter 18 Freeways
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Chapter 19 Ramps.
SHRP2 Safety Program
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Slide 18
A Quick History
What Is Naturalistic Driving Study
(NDS)?
Collecting NDS Data
SHRP2 Roadway Information Data (RID)
Collecting and Assembling RID
Using NDS in Conjunction with RID
Brain Storming.
Course Project, IHSDM Software
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Highway Safety Concepts Used in Each
Module
Setting Attributes
Mechanics of the Software
A Quick Review of Administrative Tool
Running the IHSDM Software
Reporting and Customizing Report
Templates
Interpretation of Results.
Questions ?
Slide 20
Highway Safety Manual (HSM) Part C
Implemented in IHSDM
Slide 21
HSM, Background, History, and Future
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Joint Task Force sponsored by several TRB committees
Partnership Among AASHTO, TRB and FHWA
$7 Million/10 year research program
Thousands of hours of volunteer effort of reviewing
AASHTO Joint Task Force with members from Safety,
Design and Traffic Engineering
Publication of the HSM by AASHTO (2010), Supplement
(2014)
A new TRB Committee (Highway Safety Performance)
Works to complete HSM 1st Edition and moving toward 2nd
Edition.
HSM Partitions into
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Part A
Introduction,
Human
Factors, and
Fundamentals
Part B
Roadway
Safety
Management
Process
Part C
Predictive
Method
Part D
Crash
Modification
Factors
Concepts
The expected or
actual crash frequency
and severity for a
highway or roadway
Nominal
Safety
Examined in reference
to compliance with
standards, warrants,
guidelines and
sanctioned design
procedures
Slide 24
Substantive
Safety
What is IHSDM?
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A product of FHWA’s Safety Research and
Development Program
A suite of software tools that support
project-level geometric design decisions
by providing quantitative information on
the expected safety and operational
performance
Free Distribution and Support, First
Release 2003, Latest Release 2014.
Evaluation Modules
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Crash Prediction
Policy Review
Design Consistency
Intersection Review
Traffic Analysis
Driver/Vehicle
Crash Prediction Module
Faithful implementation of the HSM Part C
Estimates expected crash frequency (i.e.,
Substantive Safety) as well as crash severity
based upon roadway geometry and traffic
volumes.
Slide 27
Relationship between IHSDM and the HSM
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B.
Introduction and Fundamentals
Roadway Safety Management Process
C. Predictive Method (IHSDM CPM)
Chapter 10: Rural, Two-Lane Roads
Chapter 11:
Rural, Multilane Highways
Chapter 12: Urban & Suburban Arterials
Chapters 18 and 19: Freeways and Ramps. Recently
published as supplements to the 1st edition of the HSM.
D.
Slide 28
Crash Modification Factors.
CPM / HSM Part C Scope
From AASHTO Website: An Introduction to Highway Safety Manual
Slide 29
CPM / HSM Part C Scope - Continue
HSM Chapter
Slide 30
Urban
Rural
18 Freeway Segments
10 Lanes
8 Lanes
18 Speed-change Lanes
10 Lanes
8 Lanes
19 Ramps and C-D
Roads
2 Lanes
1 Lanes
19 Ramp Terminals
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7 Types
Models Components
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Safety Performance Functions (SPFs)
Crash Modification Factors (CMFs)
Empirical Bayes (using crash history data)
Calibration Factors
• Enter via IHSDM Administration Tool.
Slide 31
Maximizing Safety Improvement Benefits in A
Sustainable Highway System
Cost, the Factor in Decision Making
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Construction Cost
Operational Costs, Users Cost
Environmental Costs
Crash Cost.
Maximizing Safety Improvement Benefits in A
Sustainable Highway System Continue
Network-level Maximization, Part B of the HSM
From AASHTO Website: An Introduction to Highway Safety Manual
Slide 33
Maximizing Safety Improvement Benefits in A
Sustainable Highway System Continue
Project-level Maximization, Part C of the HSM
Predicting Crashes for Different Alternatives
 Estimating Construction, Operational,
Environmental, and Crash Costs for Different
Alternatives
 Search for the Alternative with the Minimum
Total Cost.
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Other IHSDM Modules, Policy Review
Checks roadway segment
geometry against relevant design
policy and “flags” variations.
Slide 35
Other IHSDM Modules, Design Consistency
Estimates 85th percentile speed
profile along alignment to
evaluate operating speed
consistency.
Slide 36
Other IHSDM Modules, Traffic Analysis
Traffic simulation model
(TWOPAS)
 Estimates traffic quality of
service measures.
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Other IHSDM Modules, Driver / Vehicle
Slide 38
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Simulates driving behavior and
vehicle dynamics on a two-lane
highway
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Provides profiles of predicted
speed and other response
variables, via a simulation of a
single driver/vehicle
combination.
Other IHSDM Modules, Intersection Review
Slide 39
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Expert system that applies
rules of good practice in a
comprehensive diagnostic
review of a single intersection
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Identifies possible safety
concerns and typical
treatments.
IHSDM 2014 Release (10.0.0)
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May be downloaded free-of-charge at:
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Technical support:
http://www.ihsdm.org
• E-mail: [email protected]
• Phone: (202)-493-3407
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IHSDM Training (Offered by NHI):
• FHWA-NHI-380071 On-site Course
• FHWA-NHI-380100 Web-based Course
(http://nhi.fhwa.dot.gov )
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