1. Comparing Systemic Approaches: A Kentucky Example
Reg Souleyrette
2013 Traffic Records Forum
St. Paul, MN

2. TRB ‘14 paper

3. Compares 3 methods usRAP Tools software,
the FHWA systemic safety tool, and
road safety audits (RSA’s)

4. Summary All 3 are less dependent on crash data
Each method applied to the same network of KY county roads
usRAP is robust, quantitative, produces B/C (but requires much data)
FHWA method needs less data and is more flexible per data availability (but no weighting)
Audits can identify missing or poor condition features (but may miss opportunites)

5. Key Challenges Identify countermeasures
HSM Chapter 6 discusses principles
Safety Analyst deployed in 14 states but requires good crash and roadway data
Many agencies have poor crash and/or roadway data
Many roads have crashes too sparse to identify high crash locations

6. HSIP
To get project funded – identification process must be data driven
Does not have to be HCL
New methods called model-based, field-review-based, systemwide, systematic, mass action (European) or systemic
Risk-based (as opposed to history based)
Proactive, rather than reactive

7. Risk … Similar sites have similar risks Sooner or later …
Predictive models or risk factors – both tell us what?
identify and prioritize candidate improvement sites and countermeasure types when crash data are sparse or unavailable

8. Local roads Half of all serious crashes
HSIP funding nearly doubled by MAP21
Systemic useful even for states with good crash data

9. Basic Approaches
usRAP tools uses predictive models based on road and traffic data
FHWA systemic tool uses crash data to ID problems
RSAs review site-specific crash patterns, do not formally assess risk, but include a field review of sites by experts in a range of disciplines

10. usRAP tools software
~40 roadway and intersection design and traffic control features known to be related to safety
From photos each 100 meters
Star ratings for auto, bike, ped, motorcycles
70 countermeasures
B/C computed for each countermeasure

11. FHWA Systemic Tool Not software – an algorithm
Uses crash data to identify predominant crash types
Specific risk factors are selected and roads rated for how many risk factors present
Analyst may be choose simple to complex analysis

12. Road Safety Audits
team of technical professionals with a range of background and experience
review detailed crash data for each site to ID crash patterns
reviews each site in the field
identify safety improvement needs
can be either crash-data-based or risk based

13. KENTUCKY COUNTY ROAD NETWORK
219 centerline miles of county roads
six Kentucky counties rolling, hilly terrain
94 road sections, average 2.3 mi
12 fatal, 17 A-injury, and 56 B-level injury crashes ( )
average of 2.4 fatal and 14.6 injury crashes per year
estimated AADTs range from 30 to 2,850 veh/day
most sites had AADTs of 400 veh/day or less
mostly rural two-lane highways

14. usRAP Tools Analysis 88 sites (212 mi) assessed
Half Streetview®, half GPS pics
Data extracted (coded) at 20 min/mi.
$6,000,000 per fatality, $825,000 per serious injury
Discount rate of 4 percent
Countermeasure service lives and costs reviewed by the Kentucky Transportation Cabinet (KYTC) and adjusted for Kentucky conditions
Minimum benefit-cost ratios ranging from 5:1 to 10:1

15. Key Message: This series of six slides showing screen shots from the software is intended for use if a live software demonstration is not feasible. This slide shows the Road Safety Report, including a star rating map and a table of the distribution of star ratings by roadway length. Separate star ratings are included for vehicle occupants, motorcyclists, bicyclists, and pedestrians.
Background Information: None
Interactivity: None
Notes: None

16. Key Message: This series of six slides showing screen shots from the software is intended for use if a live software demonstration is not feasible. This slide shows the Safer Roads Investment Program Report. Each line summarizes the recommended implementation of a particular countermeasure for the road network as a whole. The columns on this spreadsheet represent the items listed in Slide 19. The total row at the bottom summarizes the safer roads investment program as a whole (all countermeasures combined. Clicking on the icon to the left of each countermeasure name opens a map showing the locations where implementation of that countermeasure is recommended. A downloadable Excel spreadsheet shows specific project locations in terms of road name, distance, and latitude/longitude. The drop-down menus above the table allow the user to select and display the safer roads investment program for any specific road or road section of interest.
Background Information: None
Interactivity: None
Notes: None

17. usRAP Tools Results

18. usRAP Tools Results Min BCR KSI Saved/ 20 years
Benefit/ 20 years ($ mil)
Cost/ 20
years ($ mil)
Benefit-Cost
Ratio
% Red in
Crashes 5
101
106.6
9.2
11.6
29.7 6 89
94.3
7.0
13.5
26.2 7 79
83.3
5.3
15.7
23.2 8 69
72.5
3.9
18.6
20.3 9 61
64.7
3.0
21.6
17.9 10 57
60.6
2.6
23.3
16.8

19. FHWA Systemic Safety Tool Analysis
217-mi road network
run-off-road crashes constituted 67 percent of the severe non-animal, non-intersection crashes on horizontal curves
61 percent of all run-off-road crashes and 39 percent of severe run-off-road crashes were on curves.
Target crash type was run-off-road crashes
Particular emphasis on horizontal curves

20. FHWA Systemic Safety Tool Results
Selected risk factors:
Horizontal curve density for curve radii between 500 and 1,200 ft greater than median density
Lane width less than 10.5 ft
Shoulder type not paved
Shoulder width less than 6 ft
Speed limit greater than 30 mph
Lamm et al 1999

21. FHWA Systemic Safety Tool Results
Sum of Risk Factors or “Risk Rating”
Sum of Miles
Sum of VMT (1,000s)
Count of Segments 2
2.9
1,867 3
98.2
12,658 40 4
101.2
14,127 45 5
14.7
911
Grand Total
217.2
29,563 92

22. FHWA Systemic Safety Tool Results
Average AADT by Number of Risk Factors
Weights and AADTs should be used
Sum of risk factors or
“risk rating”
Average AADT
(veh/day) 2
867 3
385 4
377 5
140

23. Road Safety Audit Analysis
22 road segments (74 mi)
RSA Team
KYTC Safety Circuit Rider
County Judge/Executive (which is an elected position in Kentucky)
County Road Supervisor/Foreman
KYTC District Traffic Coordinator
KYTC HSIP Coordinator
local law enforcement officer
other local officials

24. Road Safety Audit Results
15 countermeasures across the 22 roadway segments;
5 of the 15 countermeasures were also among those recommended in the usRAP study

25. Comparison of Results
Comparison of usRAP Star Ratings and FHWA Systemic Tool Risk Ratings by Number of Road Sections for Kentucky County Road Network

26. Comparison of Results

27. Comparison of Results

28. Comparison of Results

29. Comparison of Results

30. For more info… Reg Souleyrette, University of Kentucky