Adopting the optimization idea of rolling discrete, the real-time control framework of intersection group under the condition of over-saturation of urban road network is established.The possible phenomena of vehicle queue overflow and green light waste at the key intersections are considered and factors such as vehicle departure rate and section length of critical path are also considered.Based on that, the phase difference optimization method based on Line-axis combination is established, and the signal cycle is adjusted adaptively with the real-time saturation of key intersections as the constraint.Simulation results show that the line-axis combination method can improve the critical path capacity by 9%, reduce the overall delay of the intersection group by 7%, and effectively improve the vehicle traffic efficiency of the intersection group under the condition of supersaturation.

Intersection group; Critical path; Offset; Real-time optimization