Dynamic Straight-Right Lane Design and Signal Control at Urban Intersections

As a key node in the urban road network, the operational efficiency of urban signal intersections directly affects the general operational efficiency of road network traffic. To improve the general efficiency of the intersection considering road dimensions, site red lines, and other constraints, some signalized intersections often use a straight-right lane or a dedicated right-turn lane to right-turn vehicles in the far right lane of the entrance lane. A straight-right lane will improve the efficiency of straight-through traffic during a green light; however, straight-through vehicle will prevent right-turn vehicles from crossing the intersection. A dedicated right-turn lane will reduce delays for right-turn vehicles; however, it will not improve the efficiency of straight-through traffic. To address these issues, this paper took the basic idea of spatial and temporal separation of straight-right and right-turn vehicles on the straight-right lane as the basis for designing a dynamic straight-right lane (DSRL) organization form, and for researching key design parameters and supporting control strategies. Using hydrodynamic analogy theory, the delays of the DSRL design were compared with those of the static straight-right lane design and the dedicated right-turn lane design, the relationship between each key design parameter and vehicle delays was analyzed, and sensitivity analysis under different traffic environments was conducted. This paper presents the basic concept of DSRL design, discusses and researches its important components, and developed new ideas and methods for the design with supporting control of straight-right lanes at urban intersections.