OPERATIONAL EVALUATION OF EFFECTS RESULTING FROM FREEWAY-FREEWAY INTERCHANGE GEOMETRICS. FINAL REPORT

Improvements of freeway-freeway interchanges in Texas have been initiated through re-design and reconstruction. However, little documentation or definitive guidelines exist to assist in these efforts. Alternative designs need to be considered and evaluated for freeway-freeway interchanges. The operational impacts of alternative designs which will best accommodate current and future freeway demands must be evaluated. This research study focuses on the interaction between different freeway-freeway interchange designs and the resulting effects on operations and safety. The methodology followed to evaluate the operational effects of freeway-freeway interchange design consisted of four steps: 1) Determination of operational effects as related to different interchange types; 2) Assessments of the level and patterns of interchange accidents; 3) Analysis of geometric elements of interchanges; and 4) Case study examination of specific alternative interchange designs and improvements.