title: When driving on the left side is safe: Safety of the diverging diamond interchange ramp terminals.
abstract: How safe are the ramp terminals of a diverging diamond interchange (DDI)? This paper answered this question using data from DDI sites in Missouri. First, crash prediction models for ramp terminals for different crash severities were developed. These models were then utilized in the Empirical Bayes (EB) evaluation of DDI ramp terminals. Due to inconsistencies in crash reporting for freeways in Missouri, individual crash reports were reviewed to properly identify ramp terminal crashes. A total of 13,000 crash reports were reviewed for model development and EB evaluation. The study found that the DDI ramp terminals were safer than the conventional diamond signalized terminals. The DDI ramp terminals experienced 55% fewer fatal and injury crashes, 31.4% fewer property damage only crashes, and 37.5% fewer total crashes.
authors.affiliation: Department of Civil and Environmental Engineering, University of Missouri - Columbia, E2509 Lafferre Hall, Columbia, MO 65211, United States.
authors.forename: Boris
authors.initials: B
authors.lastname: Claros
authors.affiliation: Department of Civil and Environmental Engineering, University of Missouri - Columbia, E2509 Lafferre Hall, Columbia, MO 65211, United States. Electronic address: edarap@missouri.edu.
authors.forename: Praveen
authors.initials: P
authors.lastname: Edara
authors.affiliation: Department of Civil and Environmental Engineering, University of Missouri - Columbia, E2509 Lafferre Hall, Columbia, MO 65211, United States.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sun
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control / Q000706:statistics & numerical data*; D001334:Automobile Driving / Q000706:statistics & numerical data*; D001499:Bayes Theorem; D002138:Calibration; D004779:Environment Design / Q000706:statistics & numerical data*; D006801:Humans; D008923:Missouri; D012449:Safety / Q000706:statistics & numerical data*