Abstract:Lanzhou City is a super-large banded cluster city. For many years, the urban traffic has formed a traffic situation of "east-west congestion, north-south obstruction". In addition, the rapid increase of motor vehicles in the city in recent years has made the internal and external traffic connections more busy, which causes that the current situation that the east-west urban trunk road traffic volume is nearly saturated. Taking the Langongping Road of Nanshan (Ring) Road with the most serious traffic congestion problem as an example, the upgrading reconstruction scheme of road sections and the joints along the causeway is proposed to solve the demand of efficient traffic conversion between Xiaoxihu Channel and Nanshan (Ring) Road, give play to the east-west traffic relief capacity of Nanshan (Ring) Road, and alleviate the traffic pressure of Xijin Road and the other east-west urban trunk roads in the urban area. The research idea can provide reference for similar traffic problems.