This project provides the Texas Department of Transportation with a mechanism to conduct high-priority, limited-scope evaluations of traffic control devices. Work conducted and concluded during the 2020 fiscal year included: (1) review of retroreflective raised pavement marker practices; (2) review of optical speed bar practices in horizontal curves; (3) review of traffic signal head backplate practices; (4) review of intersection conflict warning system practices; (5) development of guidance for the application of 6-inch pavement markings; (6) assessment of the effectiveness of work zone signing; and (7) assessment of the effectiveness of pedestrian crossing treatments at night.
This project provides the Texas Department of Transportation with a mechanism to conduct high-priority, limited-scope evaluations of traffic control devices. Work conducted during the 2018 fiscal year included: Evaluation of the safety of wet-weather pavement markings, Identification of effective work zone pavement marking removal techniques, review of raised retro reflective pavement marker practices in other states, identification of current uses and effectiveness of safety corridors, hosting of a wrong-way driving forum, assessment of pedestrian crashes on freeways and high-speed arterials, review of the design and application of lane control signs on frontage roads, review of the application of embedded light-emitting diodes in signs.
This project provides the Texas Department of Transportation with a mechanism to conduct high-priority, limited-scope evaluations of traffic control devices. Work conducted and concluded during the 2019 fiscal year included: (1) Review of the application of embedded light-emitting diodes (LEDs) in signs. (2) Review of the design and application of lane control signs on frontage roads. (3) Assessment of the effectiveness of pedestrian crossing signs with embedded LEDs. (4) Assessment of pedestrian crashes on high-speed roads. (5) Review of guidance on the selection of appropriate treatment for a particular pedestrian crossing location. (6) Field evaluation of pavement marking removal and development of guidelines.
This report presents findings on three different activities conducted in the Traffic Control Device Evaluation Program during the 2016 fiscal year. The first two activities are evaluations of full-matrix color light-emitting diode changeable message signs with 20 mm pixels. The first evaluation compared legibility and detection of roadway hazard objects for signs with and without sponsor acknowledgement logos on 1/3 of the sign. A closed-course evaluation was conducted day and night on a closed course with 30 drivers traveling 30 mph. Three sign types were evaluated: green background travel time signs with white letters, black background text signs with white letters, and blue background text signs with white letters. Sponsor logos had little or no effect on sign legibility or object detection distances. When an effect was significant, it was observed only for specific types of signs or placement locations. The second activity was a nighttime evaluation of legibility of these same signs comparing three different fonts: 16 inch letters (20 x 12 pixels), 18 inch (23 x 15 pixels), and a more condensed 18 inch letter (23 x 14 pixels). The study demonstrated drivers can read messages with 18 in. letters farther away than 16 in. letters. But when expressed as legibility index, all of the fonts tested hover around the minimum legibility index of 40 ft/in recommended in the TMUTCD. This suggests that there is room for improvement in the design of individual letters. The third activity provided an update to the worksheet used to determine signal preemption needs at railroad grade crossings. The updates provide default values in some frequently used fields, eliminated some fields rarely used, and minimized the decision making for those filling out the form.
This handbook, which was developed in recognition of the need for the compilation and dissemination of information on advanced traffic control systems, presents the basic principles for the planning, design, and implementation of such systems for urban streets and freeways. The presentation concept and organization of this handbook is developed from the viewpoint of systems engineering. Traffic control studies are described, and traffic control and surveillance concepts are reviewed. Hardware components are outlined, and computer concepts, and communication concepts are stated. Local and central controllers are described, as well as display, television and driver information systems. Available systems technology and candidate system definition, evaluation and implementation are also covered. The management of traffic control systems is discussed.
