Evaluation of Guide Signing at Right Multilane Freeway Exits with Optional Lanes (1467-5)

This research study investigated guide signing practices used around the state and the rest of the nation for multilane exits. In particular, the research focused on signing for multilane exits with optional lanes. Photographs were taken of guide signing at multilane interchanges in the cities of San Antonio, Houston, Dallas, and Fort Worth, Texas. In addition, a questionnaire was sent to the state traffic engineers of each state, asking that they indicate their method of signing for a multilane exit with an optional lane and a secondary ramp split. The results of both studies indicated that a variety of signing practices for multilane exits are used in Texas and across the nation.A review of previous research showed that most drivers understand the EXIT ONLY panel, commonly used to communicate a lane drop; however, as many as one half of all drivers are confused by the current method of signing used in Texas for an optional lane at a multilane exit. Guide signing alternatives were developed to improve driver comprehension of the optional lane situation at a multilane exit. The developed alternatives were tested against the recommended method of signing in two evaluations: an initial driver survey and a laboratory study. The phrase "MAY EXIT" was found to be the best understood alternative in the initial survey. In the laboratory study, however, the differences between the various alternatives were small. The research findings indicate that the current method of signing for multilane exits should continue to be used. Additional evaluations should continue in this subject area.