TY - JOUR N2 - Starting from consideration that urban intersections are sites with promise for safety and operational improvements, the paper describes the steps taken to develop a crash predictive model for estimating the safety performance of urban unsignalized intersections located in Palermo, Italy. The focus is on unsignalized four-legged one-way intersections widespread in Italian downtowns. The sample considered in the study consist of 92 intersections in Palermo, Italy. For the study were collected crashes occurred in the sites during the years 2006‒2012, geometric design and functional characteristics and traffic flow. Results showed that data were overdispersed and NB1 distributed. In order to account for the correlation within responses Generalized Estimating Equations (GEE) were used under different working correlation matrices. L1 - http://www.czasopisma.pan.pl/Content/83917/mainfile.pdf L2 - http://www.czasopisma.pan.pl/Content/83917 PY - 2014 IS - No 1 EP - 54 KW - safety performance functions KW - urban intersection KW - overdispersion KW - correlation A1 - Giuffrè, O. A1 - Granà, A. A1 - Giuffrè, T. A1 - Marino, R. A1 - Marino, S. PB - WARSAW UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING and COMMITTEE FOR CIVIL ENGINEERING POLISH ACADEMY OF SCIENCES DA - 31.03.2014 T1 - Estimating the safety performance function for urban unsignalized four-legged one-way intersections in Palermo, Italy SP - 41 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/83917 T2 - Archives of Civil Engineering ER -