Improving Safety and Efficiency of Roundabouts Through an Integrated System of Guide Signs

A roundabout can improve intersection capacity in some extent by reducing conflict points and traffic delays. However, the complex environment in a large roundabout does not provide essential directional information to motorists. Therefore, drivers must spend more time identifying the exit they want, which may influence the intersection capacity and safety. Using perceptual constancy, a new guide sign system for roundabouts was developed to improve sense of direction. In order to observe how the guide sign system would affect drivers’ sense of direction, a series of driving simulator experiments were conducted to evaluate driving performance. The test results revealed that the guide sign system can effectively improve the accuracy of exit identification and reduce travel time driving through a roundabout despite the gender and age differences among drivers. This paper proposes a continuous and gradual guide sign system for roundabouts that can be used to help improve drivers’ sense of direction, which is beneficial to improve the safety and efficiency of roundabout operations. These findings are indicative of the future development of traffic sign design and practice in a roundabout.