1. HSM Implementation Tools Safety Analyst
Kim Kolody Silverman, PE
CH2M HILL representing
Illinois Department of Transportation
HSM Implementation
Tools
Spreadsheets
Safety Analyst
IHSDM
Summary

2. We commonly trade safety off against something else
Costs
Environment
Right-of-Way
Safety
Key Message: Virtually all decisions and judgments, whether at the program or resource allocation, or project level, involve trade-offs.
Background: Typical trade-offs include costs, traffic operational quality, safety, right-of-way, environmental and socioeconomic concerns.
Notes:
System Priorities
To Make investment decisions you need to quantify impacts

3. More quantitative Greater weight
Design
Criteria
(nominal
safety)
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
HSM Tools
More quantitative
Greater weight
Key Message: In the absence of tools for substantive safety effects, we find ourselves in the ironic position as managers of project and program development of being able to quantify environmental effects, construction costs, R/W, etc; but having little other than nominal safety (adherence to design criteria) to fall back on. The HSM provides methods, data and information to allow project decisions to be made with the same level and quality of quantitative information as is developed for other factors of interest (i.e., costs, right-of-way, traffic operations, environmental impacts)
Background: This slide illustrates that we have established and accepted tools and methods for all important considerations in highway project and program development – except for substantive safety. [Note: This is an animated slide so to review fully it should be observed in the slide mode.]
Decisions are made and will be made with the best available information. Most decisions are based on consideration of those factors for which quantitative information is available. It is generally the case that decision-making lacks a substantive safety input; if safety is considered at all it may be nominal safety. The HSM fills this substantial gap in process and information, thereby elevating safety to its proper role alongside the other important factors we look at when making choices and decisions.
Safety Environmental Traffic Right-of-Way Costs
Impacts Impacts Operations
We’re Interested in Other Impacts for Project Level Decisions – What About Substantive Safety?

4. HSM Training Module 1: Introduction
12/15/2009
Part A
Introduction Human Factors Fundamentals
Part D
Crash Modification Factors (CMFs)
Part B
Roadway Safety Management Process
Part C
Predictive Method
Roadway safety fundamentals
Safety management process
Models for estimating the expected safety performance of a specific facility
Crash modification factors for estimating the expected effectiveness of individual infrastructure-based countermeasures
Key Message: The HSM focuses on quantifying safety within the planning, design, operations and maintenance functions.
Background Information: The first edition does not cover driver education, enforcement, and vehicle safety, even though we realize that these are important elements which can help reduce injuries and fatalities from motor vehicle crashes.
The HSM is divided into four parts. In part A the user is provided with an introduction to the HSM, knowledge about human factors and the fundamentals of highway safety. Part B covers the roadway safety management process. In Part C predictive methods are introduced for different facility types. And, last but not least, Part D provides Crash Modification Factors (CMFs) for use with Part B. It is important to keep in mind that Part D can only be used with Part B – Part C has its own AMFs for each facility type. This issue is further addressed later in our discussion.
Presentation Handouts

5. Tools for Implementing HSM
Excel Spreadsheets
Interactive Highway Safety Design Model (IHSDM)
Safety Analyst

6. HSM Excel Spreadsheets
Project level basis
Simple, straightforward
Limited data required
Worksheet 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
2.9
Intersection 2
Intersection 3
COMBINED (sum of column)
9.448
3.300
6.147 15 --
12.3
Developed by FHWA and NCHRP
Input:

7. Interactive Highway Safety Design Model
Provides expected safety, operational performance
HSM techniques +
Modules to compare design to standards
Requires detailed data input
Free
It checks existing or proposed highway designs against relevant design policy values and provides

8. The Vision of SafetyAnalyst – Software Akin to the HCS+1
Definitive; represents quantitative ‘state-of-the-art’ information
Widely accepted within professional practice of transportation engineering
Science-based; updated regularly to reflect research 2
The Highway Capacity Manual is acknowledged as the recognized source of information and methodologies for quantitatively evaluating traffic operations on streets and highways. As a consequence, engineering studies and reports that use the HCM are unquestioned with respect to the results. The HCM contents are based on peer-reviewed, science-based research; and the HCM is continually updated and improved as more research is completed.
No such document exists in the field of quantitative highway safety. While there is quantitative safety information available, much of it is in conflict, may not reflect the best scientific methods, or is unclear in its content and background. Engineers and planners, who need to include quantitative safety information in their work, are left to their own knowledge base and must not only make judgments about what data or methods to use, but they must also defend their judgment.
The HSM is a toolbox for assessing quantitative safety effects of decisions or actions – nothing more. It provides direction on how to use each of the tools contained within it, and how to interpret and communicate the results. It also provides direction on which tools are appropriate to use in a given situation or given the amount and quality of data available. The HSM provides the user with the tools to assess different alternatives to reduce crash frequency or severity.
With publication of an HSM, users can refer to it with confidence that it reflects best practices and knowledge and that it has been “vetted” by highway safety research professionals.
Notes:
Quantification of Decision Making 3

9. 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 making
Efficiency of decision support
Effectiveness of decision making:
Automates state-of-the-art statistical approaches described in the Highway Safety Manual (Part B) to improve the identification and programming of site-specific highway safety improvements
Efficiency of decision support:
Integrates all parts of the safety management process in a single, modular software package

10. Intended for those who will:
Identify candidate sites for safety improvements
Investigate the types of safety improvements needed for specific sites
Assess whether specific safety improvements are economically justified and should be programmed
Evaluate the safety effectiveness of implemented projects

11. Road Safety Management Process
Network Screening
Diagnosis & Countermeasure Selection
Economic Appraisal & Prioritization
Safety Effectiveness Evaluation
Identification of sites with potential for safety improvement
Diagnosis of the nature of safety concerns at specific sites
Selection of potential countermeasures at specific sites
Economic appraisal for sites and countermeasures under consideration
Priority rankings of improvement projects
Safety effectiveness evaluation of implemented countermeasures
Module 1 – 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
Module 2 – Diagnosis and Countermeasure Selection
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 3 – Economic Appraisal and Priority Ranking
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 4 – Countermeasure Evaluation
Conduct before-after evaluations of implemented countermeasures
Quantify the safety effectiveness of implemented countermeasures based on:
Percent change in accident frequency
Change in proportion of target accidents

12. Module 1
Network Screening
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
Network screening
Scientific state-of –the-art procedures
Consistent evaluation
Flexible for user
Leads to better selection of sites due to various methods based on the latest research
Types of network screening:
Basic network screening for sites with high accident frequencies, peak searching or sliding window
High proportion of specific accident type
Sudden increase in mean accident frequency
Steady increase in mean accident frequency
Corridor screening (extended roadway sections)

13. Diagnosis & Countermeasure Selection
Module 2
Diagnosis & Countermeasure Selection
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
Collision diagrams
Provides simple collision diagram capabilities
Third-party software can be linked
Accident summary statistics
Generates table, bar-charts, and/or pie-charts for range of accident data elements
Statistical tests
Test for minimum accident frequencies
Test for high proportions of accidents
Diagnostic Investigations
Conduct diagnostic investigations
software asks diagnostic questions
Software suggests countermeasures that address identified accident patterns
User selects appropriate countermeasures

14. Economic Appraisal & Prioritization
Module 3
Economic Appraisal & Prioritization
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
Economic Appraisal and Ranking Measures
Cost effectiveness
EPDO-based cost effectiveness
Benefit-cost ratio
Net benefits
Construction costs
Safety benefits
Number of total accidents reduced
Number of FI accidents reduced
Number of FS accidents reduced
Benefits
Current economic analysis procedures are recognized in HSIP
Multiple economic appraisal approaches can be applied
Can be used for economic evaluation of a single site or multiple sites
Safety effectiveness information (AMFs) for countermeasures available from national research
Can be updated, or supplemented, based upon safety performance at local sites

15. Module 4 – Countermeasure Evaluation
Safety Effectiveness Evaluation
Conduct before-after evaluations of implemented countermeasures
Quantify the safety effectiveness of implemented countermeasures based on:
Percent change in accident frequency
Change in proportion of target accidents

16. Test Data Input for Illinois
Category
Test Areas
3 Counties
1 Township
Route Type
State and Local facilities
Number of roadway segments
28,093
Roadway mileage
7,471
Number of intersections
18,704
Number of crashes
118,093
Note:
Counties are Champaign, Sagamon, Vermillion and the township is West Chicago
Crashes represent 2005 to 2009 fatal, A-injury, B-injury, C-Injury, and PDO
SA is an incredibly powerful tool that will make our lives much easier, but need to start working on setting up the data sooner rather than later. It can be time consuming.
3 counties + 1 township in Chicago  (Champaign, Sangamon, Vermilion…plus West Chicago Township)
Number of segments?   28,093
Mileage?  7,471 miles
Number of intersections?  18,704
Number of crashes?    118,093
Does the number of crashes include K, A, B, C, PDO?  yes
Import – 3.5 hrs
Run Crash Script hours
Post Processing  2.5 hrs
Calibrate hours
Total time *  = 6.5 hours for approximately 5% of our data. 
* Time estimates do not include the prep-work to derive our source files for intersections.  We are utilizing several GIS functions to calculate some of the fields that are needed. 
Data Element
Washington Records
Roadway Segments
705,962
Intersections
11,847
Collisions ( )
238,810
Ohio Records
34,275 (19,499 miles)
45,915
Collisions ( )
1,415,393

17. Data Process for Illinois
3.5 hours for data import
15 minutes for crash data script
2.5 hours for post processing
15 minutes for calibration
Total = 6.5 hours
for approximately 5% of total data set
SA is an incredibly powerful tool that will make our lives much easier, but need to start working on setting up the data sooner rather than later. It can be time consuming.
3 counties + 1 township in Chicago  (Champaign, Sangamon, Vermilion…plus West Chicago Township)
Number of segments?   28,093
Mileage?  7,471 miles
Number of intersections?  18,704
Number of crashes?    118,093
Does the number of crashes include K, A, B, C, PDO?  yes
Import – 3.5 hrs
Run Crash Script hours
Post Processing  2.5 hrs
Calibrate hours
Total time *  = 6.5 hours for approximately 5% of our data. 
* Time estimates do not include the prep-work to derive our source files for intersections.  We are utilizing several GIS functions to calculate some of the fields that are needed. 
Data Element
Washington Records
Roadway Segments
705,962
Intersections
11,847
Collisions ( )
238,810
Ohio Records
34,275 (19,499 miles)
45,915
Collisions ( )
1,415,393

18. Challenges Data input and processing takes some time
Requires user training
Requires agency support
Cost

19. Challenges Data Input and Processing
Coordinate multiple data sources, data owners
Determining business rules
Complete data where not available
Data input (SQL vs Oracle)
Data set-up process time
Network screening process time

20. Benefits Powerful analysis tool Automates HSM procedures
Calibrates national default SPFs
Screen large amounts of data
Provides consistent evaluation and results for decision making

21. Benefits Flexible for user
Countermeasures, service life, costs included
Automates various economic comparisons
Set of tools that allows for a better selection of sites and improved prioritization techniques for decision making to maximize resources to reduce severe crashes

22. Benefits Forces coordination between divisions of the agency
Better data
More data
Understanding of data application across the agency which may influence potential changes in agency business practices

23. HSM Implementation Tool: Recommendations
Use HSM Excel Spreadsheets where appropriate
Apply IHSDM where appropriate
Start preparing Safety Analyst for use

24. HSM Implementation Tool: Safety Analyst Recommendations
Determine funding options
Start the process of data identification, mapping
Start educating staff at central office
Engage IT staff

25. 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

26. For more information Highway Safety Manual
Safety Analyst
Interactive Highway Safety Design Model

27. Illinois Department of Transportation
Questions
Priscilla Tobias, PE
State Safety Engineer
Illinois Department of Transportation
(217)
Kim Kolody, PE
CH2M HILL
(773)