Application of the AASHTO Highway Safety Manual (HSM)

39 Pages·2015·3.07 MB·English

Application of the AASHTO
Highway Safety Manual (HSM)
Karen Dixon, Ph.D., P.E.
Email: [email protected]
1
HSM Overview
2
Integrate Safety
Need
into Decision
Processes
3
Safety Trade-Offs?
Costs
Environment
Safety Right-of-Way
What Do You Do?
4
Highway Safety has Two
Dimensions
Nominal
Substantive
Safety
Safety
Standards Expected or Actual
Compliance Crash Frequency
and Severity
5
Design Exception Insights
Nominal Safety is
an ABSOLUTE
r
e
t
a
e
r
G
K
S
I
R

H
S Substantive
A
R
Safety is a
C
CONTINUUM
Greater
DESIGN DIMENSION
6
HSM Vision Akin to HCM
1 Definitive; represents
quantitative ‘state-of-the-
art’ information
2 Widely accepted within
professional practice of
transportation engineering
3
Science-based; updated
regularly to reflect research
7
Common Impacts for
Project Level Decisions?
• Traffic Noise • Traffic • Cost Models
Design
Models Operations / • Real Estate
Criteria
• Air Quality Models Microscopic Appraisals
(nominal
• 3-D Visualization Simulation • DOT
e
safety)
v • Environmental • Construction Databases t
i h
t
a Assessments Plans g
t i
i e
t
n The HSM W
a

u r
e
Q
t
Substantive Safety a

e e
r r
o G
M
Safety Environmental Traffic Right-of-Way Costs
Impacts Impacts Operations
8
Design
Existing Conditions Alternative 1
Alternative 2 Alternative 3 9
>> 0 >> 1 >> 2 >> 3 >> 4 >>
Vol. 1 (Part A)
Vol. 3 (Part D)
Introduction
Crash Modification
Human Factors
Factors (CMFs)
Fundamentals
Vol. 1 (Part B)
Vol. 2 (Part C)
Roadway Safety
Management Predictive Method
Process
10