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DOI: 10.7708/ijtte.2013.3(3).02

3 / 3 / 243-259 Pages


Sascia Canale - Department of Civil and Environmental Engineering, University of Catania, Italy -

Natalia Distefano - Department of Civil and Environmental Engineering, University of Catania, Italy -

Salvatore Leonardi - Department of Civil and Environmental Engineering, University of Catania, Italy -


The ISAT algorithm (Interchange Safety Analysis Tool), developed by the Federal Highway Administration (FHWA), provides design and safety engineers with an automated tool for assessing the safety effects of geometric design and traffic control features at an existing interchange and adjacent roadway network. Concerning the default calibration coefficients and crash distributions by severity and type, the user should modify these default values to more accurately reflect the safety experience of their local/State agency prior to using ISAT to perform actual safety assessments. This paper will present the calibration process of the FHWA algorithm to the local situation of Oriental Sicily. The aim is to realize an instrument for accident forecast analyses, useful to Highway Managers, in order to individuate those infrastructural elements that can contribute to improve the safety level of interchange areas, if suitably calibrated.

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