Abstract: This paper describes the construction of a time-space diagram. The formation conditions of green wave are proposed on the basis of the vehicle kinematic characteristics between closely spaced intersections. With regard to adjacent three-leg intersections along a two-way arterial, an autocorrelated phase scheme is designed from phase numbering, phase combinations and phase sequences. The primary time-space relationships and their variations demonstrated by the two-axis time-space diagram are explained by an analytic method. With these, the cross-correlated phase scheme that facilitates the generation of ideal two-way green wave can be easily filtered out from the autocorrelated phase scheme and some guidance on coordinated signal timings can be concluded. The sample results indicate that the proposed design method of phase scheme is simple and practical, and will substantially contribute to the planning and implementation of two-way green wave.

Key words: transportation engineering, traffic signal, three-leg intersections, green wave, time-space diagram, phase scheme