In recent years, the State of Indiana has built a number of intersections where one or both of the roads are located on curves. The AASHTO Policy on Geometric Design of Highways and Streets recommends that in such cases “the alignment should be as straight and the gradient as flat as practical.” This wording, consistent with Part V of the Indiana Design Manual, allows for the design of intersections on curves if other solutions prove to be too expensive. Several of these intersections have raised safety concerns and led to expensive corrective measures. Due to these safety and economic issues, INDOT currently avoids designing intersections on segments with steep superelevation. The focus of this research is to determine what effect curvature and superelevation have on intersection safety. Based on the results, the goal is to provide design standards for curvature and superelevation for cases where the major road is located on a superelevated curve.

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Intersection, Superelevation, Curvature, Safety, SPR-2797

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Performing Organization

Joint Transportation Research Program

Publisher Place

West Lafayette, IN

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