road safety impact assessment irf psarianos 2011
DESCRIPTION
Difficulties in Implementing the Road Safety Impact Assessment processTRANSCRIPT
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011
{ Road Safety Impact Assessment
Quantification Challenges for Worldwide Application
Basil Psarianos, Professor National Technical University of Athens, Greece
International Road Federation
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 2
Directive 2008/96/EC on Road Infrastructure Safety Management ONLY for the Trans-European Road Network
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 3
Road Safety Impact Assessment: A Proactive Design Decision Process for Road Safety
Road Safety Impact
Assessment
Road Safety Audits
Road Safety Inspections
Road Network
Safety Management
P R O A C T I V E
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 4
Strategic Level of Decision Making for Road Design and Planning
New Roads and Substantial Modifications of existing Roads
Safety Implications of Design and Planning Alternatives
Safe Route Planning
All Road Projects
Prerequisite for Approval of any Road Project
Safety Considerations associated with Alternative selected
Cost-beneficial Component of Alternative
AIM of RIA for New & Old Roads
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 5
Elements of a road safety impact assessment: (a) problem definition; (b) current situation and ‘do nothing’ scenario; (c) road safety objectives; (d) analysis of impacts on road safety of the proposed alternatives; (e) comparison of the alternatives, including cost-benefit analysis; (f) presentation of the range of possible solutions.
Elements to be taken into account: (a) fatalities and accidents, reduction targets against ‘do nothing’ scenario; (b) route choice and traffic patterns; (c) possible effects on the existing networks (e.g. exits, intersections, level crossings); (d) road users, including vulnerable users (e.g. pedestrians, cyclists, motorcyclists); (e) traffic (e.g. traffic volume, traffic categorization by type); (f) seasonal and climatic conditions; (g) presence of a sufficient number of safe parking areas; (h) seismic activity.
RIA Content
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 6
Denmark
Germany
Finland
Lithuania
Netherlands
Portugal
Slovakia
RIA: An Old Story (more or less) for some Members States
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 7
One Dimensional (Major Roadwork, Road Facility, Reconstruction) Engineering Judgment Literature Review Local Network Impact C-B Analysis
Two Dimensional (Areal Level) Baseline Situation (year 0) Future Situation w/o Measures (Autonomous
Development) Road Safety Alternatives C-B Analysis Optimization of Alternatives for best C-B ratio
Two Types of RIA
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 8
The Achilles Heel: Quantification
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 9
Road Safety?
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 10
Safety Impact Assessment
There is actually NO Safety!
Instead there is RISK
RISK (R) is a combination of Crash Severity (SH) and its Probability (p):
R=SH*p or
d(SH)p(SH)R
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 11
VII SEMINARIO
A:Local Entrance Street
B:Local Entrance Street
C:Shopping Street
D:Central Square
E:Shopping Street
F:Local Entrance Street
G:Local Entrance Street
Different Sections and Characters (after H. Heinz)
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 12
Can Someone define EXACTLY for each Section the appropriate:
Design Speed?
Cross-Section?
Curvature?
Intersection Form and Type?
Equipment?
Traffic Characteristics?
ETC?
Safety Impact Assessment
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011
{
13
Evidence-Based Road Safety: The conscientious and judicious use of current best evidence in providing
road safety for individuals, facilities, and transportation systems.
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 14
Safety Impact Assessment
CrashesofNumber
VictimsofNumber
Exposure
CrashesofNumberExposureimpactRoadsafety
__
____
RISK LOSS
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 15
Usual Prediction Model
• E(λ)=Expected Number of Accidents • Q=Traffic Volume for Major & Minor
Road • β=Elasticity • γi=Coefficients • xi=Risk Factors •
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 16
Example: Motorways
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 17
Accident Modification Factors (AMF)
Accident Modification Factor is a constant or equation that represents the change in safety following a change in the design or operation of a facility.
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 18
Crash Reduction Factor: CRF
Crash Reduction Factor is a constant that represents the portion of crashes reduced as a result of a safety improvement (e.g., add a left-turn bay) at a specific location or along a specific road segment.
Crash Reduction Factor: CRF
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 19
CRF:
CRF 1Nw
Nw /oCRF = crash reduction factor associated with a specific improvement; Nw = expected number of crashes with the improvement, crashes/yr; and Nw/o = expected number of crashes without the improvement, crashes/yr.
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 20
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 21
Volumes change on Network: RIA on Network
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 22
Volumes???
Motorway Korinthos-Patra
Motorway Attiki Odos
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 23
Experience on Traffic Forecasts
Source: Halkias, B., Tyrogianni; H.:
PPP Projects in Greece: The Case of Attika Tollway, Route-Roads No. 342, 2008
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 24
% Errors in Traffic Forecasts (Flybjerg et al., 2006)
underestimation overestimation
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 25
GIS-Support Tool
Input
•Accident Data
•Network Data
•Road Characteristics
•User Behavior
•Etc
Intervention Scenarios
•Technical
•Juridical
•Etc
Output
•Total Costs of Measures
•Crash Modifications
•Presentation of Alternative Measures (scenarios) for comparison
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 26
SEROES Expert System
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 27
Safety Impact Assessment: Example
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 28
Safety Impact Assessment: Example continued
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 29
Safety Impact Assessment: Cost?
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 30
Cost-Benefit Analysis By EZRA HAUER
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 31
Cost-Benefit Analysis
By Ezra Hauer, TRB 2011
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 32
Cost-Benefit Analysis
By Ezra Hauer, TRB 2011
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 33
Cost-Benefit Analysis
By Ezra Hauer, TRB 2011
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 34
Public Consensus: For Example Access Management
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 35
Public consensus, ie is prohibition of property access possible?
Typical Example: people assess property rights higher than road safety
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 36
Road Safety Impact Assessment
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 37
RIA: Conclusions
QUANTIFICATION PROBLEMS
Knowledge Gap
Data Sets
Modelling
Calibration Factors
Statistical Evidence
Traffic Forecasting
CBA Weaknesses
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 38
RIA: Conclusions
Setup a Plan and Action Program at International / EU and National / Local Level to address the quantification problems of Road Safety Impact Assessment and get the public consensus for it!
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 39
RIA: Conclusions
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 40
Engineer’s Role in Informal RIA Application
SAFETY: NOMINAL vs SUBSTANTIVE SAFETY i.e.
Guidelines vs Performance, or
Rhetoric vs Reality
FLEXIBILITY to make Professional Design Choices AND Assuming Responsibility for them
PRACTICAL DESIGN
RIA: Conclusions
Providing Infrastructure that improves Road Safety Bucharest, May 10-11, 2011 41
Basil Psarianos, Nat’l Tech. Univ. Athens, Greece
International Road Federation