Human Factors Considerations in the Selection of a Uniform Protected/Permitted Left-Turn Signal Display

Transportation engineering encompasses a wide array of topics related to the movement of people and goods. Given this broad diversity, very few components of transportation engineering, including the design and implementation of signalized intersections, can be fully developed without integrating an understanding of human factors. Human factors applies information about human behavior, abilities, limitations, and other characteristics to the design of environments for productive, safe, and effective human use. Specifically, human factors can be defined as the study of how drivers accomplish driving-related tasks in the context of driver-vehicle system operation, and how behavioral variables affect this accomplishment. Further, in the control of vehicular movements at signalized intersections, human factors provides insight and understanding into drivers’ processing of and reaction to traffic signal display information.