kim kolody silverman, pe ch2m hill representing illinois department of transportation
TRANSCRIPT
HSM Implementation ToolsSafety AnalystKim Kolody Silverman, PECH2M HILL representing
Illinois Department of Transportation
We commonly trade safety off against something else
Safety Right-of-Way
Costs
Environment
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)
Mor
e qu
antit
ativ
e
Gre
ater
wei
ght
HSM Tools
3
Part AIntroduction
Human Factors Fundamental
s
Part D Crash
Modification Factors (CMFs)
Part B
Roadway Safety Management
Process
Part CPredicti
ve Method
Tools for Implementing HSMExcel SpreadsheetsInteractive Highway Safety Design
Model (IHSDM)Safety Analyst
HSM Excel Spreadsheets
Project level basisSimple,
straightforwardLimited data
requiredWorksheet 3A -- Predicted and Observed Crashes by Severity and Site Type Using the Site-Specific EB Method
(1) (2) (3) (4) (5) (6) (7) (8)Site type
Predicted average crash frequency (crashes/year)
Observed crashes,
Nobserved (crashes/year)
Overdispersion Parameter, k
Weighted adjustment, w
Expected average crash
frequency, Nexpected
N predicted (TOTAL)
N predicted (FI)
N predicted (PDO)
Equation A-5 from Part C Appendix
Equation A-4 from Part C Appendix
ROADWAY SEGMENTS
Segment 1 6.106 1.960 4.146 10 0.157 0.510 8.0
Segment 2 0.495 0.159 0.336 2 2.360 0.461 1.3
Segment 3 1.000 0.0
INTERSECTIONS
Intersection 1 2.847 1.181 1.665 3 0.540 0.394 2.9Intersection 2
1.000 0.0
Intersection 3
1.000 0.0
COMBINED (sum of column) 9.448 3.300 6.147 15 -- -- 12.3
Interactive Highway Safety Design Model
Provides expected safety, operational performance
HSM techniques +Modules to compare
design to standardsRequires detailed data
inputFree
The Vision of SafetyAnalyst – Software Akin to the HCS+
Definitive; represents
quantitative ‘state-of-the-art’
information
Widely accepted within professional
practice of transportation engineering
Science-based; updated regularly to
reflect research
1
2
3
Purpose of SafetyAnalyst
SafetyAnalyst provides state-of-the-art tools for safety management that provide capabilities beyond those currently available to highway agencies
Effectiveness of decision makingEfficiency of decision support
Intended for those who will:Identify candidate sites for safety
improvementsInvestigate the types of safety
improvements needed for specific sitesAssess whether specific safety
improvements are economically justified and should be programmed
Evaluate the safety effectiveness of implemented projects
Road Safety Management Process
Network Screening
Diagnosis & Countermeasure Selection
Economic Appraisal & Prioritization
Safety Effectiveness Evaluation
Network Screening
Review highway network (or any portion of the network) to identify sites with potential for safety improvement
Identify sites that are candidates for further investigation
6 different methods for screening
Module 1Network Screening
Helps to identify accident patterns of interest at specific sites
Guides user in the diagnosis of safety problems at specific sites
Suggests countermeasures that address identified accident patterns of interest
Lets user select appropriate countermeasures
Module 2 Diagnosis & Countermeasure Selection
Perform economic analysis of alternative countermeasures for a specific site
Perform economic analysis of countermeasures across selected sites
Select mix of sites and countermeasures to maximize benefits within a given budget
Develop priority ranking of alternative improvements
Module 3Economic Appraisal & Prioritization
Conduct before-after evaluations of implemented countermeasures
Quantify the safety effectiveness of implemented countermeasures based on:Percent change in accident frequencyChange in proportion of target
accidents
Module 4 – Countermeasure Evaluation
Safety Effectiveness Evaluation
Test Data Input for IllinoisCategoryTest Areas 3 Counties
1 TownshipRoute Type State and Local
facilitiesNumber of roadway segments
28,093
Roadway mileage 7,471Number of intersections 18,704Number of crashes 118,093Note: Counties are Champaign, Sagamon, Vermillion and the township is West ChicagoCrashes represent 2005 to 2009 fatal, A-injury, B-injury, C-Injury, and PDO
Data Process for Illinois
3.5 hours for data import15 minutes for crash data
script2.5 hours for post processing
15 minutes for calibration
Total = 6.5 hours for approximately 5% of total data
set
Challenges
Data input and processing takes some time
Requires user trainingRequires agency supportCost
Challenges
Data Input and ProcessingCoordinate multiple data sources, data
ownersDetermining business rules Complete data where not availableData input (SQL vs Oracle)Data set-up process timeNetwork screening process time
Powerful analysis toolAutomates HSM proceduresCalibrates national default SPFsScreen large amounts of dataProvides consistent evaluation and
results for decision making
Benefits
Flexible for userCountermeasures, service life, costs
includedAutomates various economic
comparisonsSet of tools that allows for a better
selection of sites and improved prioritization techniques for decision making to maximize resources to reduce severe crashes
Benefits
Forces coordination between divisions of the agencyBetter dataMore dataUnderstanding of data application
across the agency which may influence potential changes in agency business practices
Benefits
HSM Implementation Tool: Recommendations
Use HSM Excel Spreadsheets where appropriate
Apply IHSDM where appropriate
Start preparing Safety Analyst for use
Determine funding options
Start the process of data identification, mapping
Start educating staff at central office
Engage IT staff
HSM Implementation Tool: Safety Analyst Recommendations
Start with a small test data set
Good team coordination
Decision making in data set-up
Seek assistance from AASHTO, peers
HSM Implementation Tool: Safety Analyst Recommendations
For more informationHighway Safety Manual
http://www.highwaysafetymanual.org/
Safety Analyst http://www.safetyanalyst.org/
Interactive Highway Safety Design Modelhttp://www.tfhrc.gov/safety/ihsdm/ihsdm.htm
Questions
Kim Kolody, PECH2M HILL
(773) [email protected]@illinois.gov
Priscilla Tobias, PEState Safety EngineerIllinois Department of
Transportation(217) 782-3568