Document Type


Date of Award



College of Science, Engineering, and Technology (COSET)

Degree Name

MS in Transportation Planning & Management

First Advisor

Dr. Qiao


Recently growing congestion on the transportation networks has been a substantial threat to the economy and quality of life of millions of people around the world. Express or toll lanes is one of the new transportation demand-management strategies to improve traffic congestion on freeways. The functional congestion pricing strategies vary with roadway operations and facility geometries. Even though several practices all over the United States and the world are observed there is a lack of guidelines on congestion pricing message signs over a state and the country. This study is intended to propose a workable procedure to test the pricing message signs, and provide general recommendations of congestion based pricing sign design as a reference to field engineers. Preliminary congestion based pricing sign design was designed by referring current practices and the new version of Manual on Uniform Traffic Control Device. Driving simulator test was selected as a tool to examine drivers' understanding of designed pricing signs. 4 scenarios with 16 testing congestion based pricing signs were designed. A total of 30 subjects recruited of gender, age, and educational level to represent Houston's 1 2 demographics data. Post-test questionnaires were distributed to col1ect drivers' answers and opinions about pricing sign design immediately after the simulator test. After analyzing data from the driving simulator test output and the post-test questionnaires through ANOVA test, signs with drivers' best understandings were identified. Design of these signs was based on fol1owing principles: (a) white background of pricing sign; (b)no more than three lines on a sig; (c)HOV 2+ NO TOLL to display vehicle occupancy requirements; (d)no more than two destinations to be displayed; (e)the closest destination is presented the first; (f)destinations are presented by highways logos, and non-existent numbers of interstate highways; (g)payments methods (TxTag, PAY BY MAIL) are presented by the logos. The several important recommendations that can improve drivers' comprehension of congestion based pricing signs include: (a) present information using the minimum number of lines on a sign (one or two); (b) place the same type of information (tol1 rates or payment methods) on one sign; (c) separate price information from travel time; and (d) repeat tol1 rates signs if possible.