TY - JOUR
T1 - Safety evaluation of the safetyedge treatment for pavement edge drop-offs on two-lane rural roads
AU - Lyon, Craig
AU - Persaud, Bhagwant
AU - Donnell, Eric
N1 - Funding Information:
This work was managed by Dr. Carol Tan of the Federal Highway Administration. Additional technical guidance was offered by Cathy Satterfield and Christopher Wagner from FHWA. The authors wish to acknowledge their vision and guidance to the project. This work is based on data provided by Iowa, North Carolina, Ohio, Pennsylvania, and Florida. The support of the state transportation agencies in providing data and advice is gratefully acknowledged.
Publisher Copyright:
© National Academy of Sciences: Transportation Research Board 2018.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - This study estimated crash modification factors (CMFs) for the SafetyEdge paving technique that is applied for the treatment of pavement edge drop-offs on two-lane rural highways. An empirical Bayes observational before-after evaluation based on installation data in Iowa, North Carolina, Ohio, Pennsylvania, and Florida found that the SafetyEdge treatment was associated with statistically significant reductions in fatal and injury (FI), run-off-the-road (ROR), opposite-direction (head-on and sideswipe), and drop-off-related crashes. The ROR CMF was also statistically significant for both horizontal curved and tangent sections. A disaggregate analysis examined the variation of the CMF for ROR with factors such as the travel lane width, traffic volume, presence of a horizontal curve, posted speed limit, and the pre-treatment ROR crash frequency. The results of that analysis indicated, for example, that the SafetyEdge paving technique appears to have a greater ROR safety benefit on two-lane rural roadway segments with average annual daily traffic volumes greater than 3,000 vehicles per day, relative to roadway segments with lower traffic volumes. A crash modification function (CMFunction) was calibrated with expected pre-treatment ROR crashes as the independent variable to simultaneously capture the relationship of the CMF for ROR crashes to multiple factors. An economic analysis found that the treatment is highly cost-effective.
AB - This study estimated crash modification factors (CMFs) for the SafetyEdge paving technique that is applied for the treatment of pavement edge drop-offs on two-lane rural highways. An empirical Bayes observational before-after evaluation based on installation data in Iowa, North Carolina, Ohio, Pennsylvania, and Florida found that the SafetyEdge treatment was associated with statistically significant reductions in fatal and injury (FI), run-off-the-road (ROR), opposite-direction (head-on and sideswipe), and drop-off-related crashes. The ROR CMF was also statistically significant for both horizontal curved and tangent sections. A disaggregate analysis examined the variation of the CMF for ROR with factors such as the travel lane width, traffic volume, presence of a horizontal curve, posted speed limit, and the pre-treatment ROR crash frequency. The results of that analysis indicated, for example, that the SafetyEdge paving technique appears to have a greater ROR safety benefit on two-lane rural roadway segments with average annual daily traffic volumes greater than 3,000 vehicles per day, relative to roadway segments with lower traffic volumes. A crash modification function (CMFunction) was calibrated with expected pre-treatment ROR crashes as the independent variable to simultaneously capture the relationship of the CMF for ROR crashes to multiple factors. An economic analysis found that the treatment is highly cost-effective.
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U2 - 10.1177/0361198118758054
DO - 10.1177/0361198118758054
M3 - Article
AN - SCOPUS:85045247688
SN - 0361-1981
VL - 2672
SP - 1
EP - 8
JO - Transportation Research Record
JF - Transportation Research Record
IS - 30
ER -