TY - JOUR
T1 - Appraisal of the interactive highway safety design model's crash prediction and design consistency modules
T2 - Case studies from Pennsylvania
AU - Donnell, Eric T.
AU - Gross, Francis
AU - Stodart, Brandon P.
AU - Opiela, Kenneth S.
PY - 2009
Y1 - 2009
N2 - The interactive highway safety design model (IHSDM) is a suite of software analysis tools used to evaluate safety and operational effects of geometric design on two-lane rural highways. IHSDM checks existing or proposed two-lane highway designs against relevant design policy values and provides estimates of a design's expected safety and operational performance. This paper describes efforts to apply IHSDM to two existing rural roadways (one an arterial and the other a collector) in Pennsylvania and to compare the crash prediction and speed profile results to observed speed and crash data for these same two roadway segments. When considering both case study roadways together, the use of site-specific crash history data, adjusted using the empirical Bayes procedure, and a county-level calibration factor, produced crash frequency predictions that most closely matched the observed crash frequencies. The design consistency module output on the arterial roadway closely matched the observed speeds. On the collector roadway, the predicted and observed speeds did not match closely, thus, underscoring the need to expand the design consistency module capabilities to consider low-speed, complex alignments.
AB - The interactive highway safety design model (IHSDM) is a suite of software analysis tools used to evaluate safety and operational effects of geometric design on two-lane rural highways. IHSDM checks existing or proposed two-lane highway designs against relevant design policy values and provides estimates of a design's expected safety and operational performance. This paper describes efforts to apply IHSDM to two existing rural roadways (one an arterial and the other a collector) in Pennsylvania and to compare the crash prediction and speed profile results to observed speed and crash data for these same two roadway segments. When considering both case study roadways together, the use of site-specific crash history data, adjusted using the empirical Bayes procedure, and a county-level calibration factor, produced crash frequency predictions that most closely matched the observed crash frequencies. The design consistency module output on the arterial roadway closely matched the observed speeds. On the collector roadway, the predicted and observed speeds did not match closely, thus, underscoring the need to expand the design consistency module capabilities to consider low-speed, complex alignments.
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U2 - 10.1061/(ASCE)0733-947X(2009)135:2(62)
DO - 10.1061/(ASCE)0733-947X(2009)135:2(62)
M3 - Article
AN - SCOPUS:58549095279
SN - 0733-947X
VL - 135
SP - 62
EP - 73
JO - Journal of Transportation Engineering
JF - Journal of Transportation Engineering
IS - 2
ER -