In order to assess driver assumptions about lane assignments on frontage roads approaching interchanges and complex intersections, TTI researchers conducted a literature review, practitioner survey, focus groups, driver computer-based survey, and finally a field test. Safety Center researchers’ contribution to the project primarily was the design and completion of the focus groups and computer-based surveys.
Both studies focused on determining what drivers believe will happen to each of the lanes at frontage and arterial road intersections, and what roadway geometry may violate their expectations. The studies also evaluated drivers’ understanding of current and new concept signs and markings for lane assignment applications.
Based on the data from these studies a field test of several new concept signs, a set of guidelines was delivered to TxDOT to assist in the best signing and marking practices at these types of intersections.