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

TRB ‘14 paper

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

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)

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

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

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

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

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

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

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

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

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 (2007-11) 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

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

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

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

usRAP Tools Results

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

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

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

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

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

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

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

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

Comparison of Results

Comparison of Results

Comparison of Results

Comparison of Results

For more info… Reg Souleyrette, University of Kentucky Souleyrette@uky.edu 859-257-5309 www.usrap.us www.fhwa.dot.gov