Study On Dynamic Design Of Traffic Organization In Freeway Reconstruction Engineering

After twenty years of freeway construction, the number of freeway has been close to or exceeding the design life now.Traffic on some freeways has exceeded the design capacity,and there has been the phenomena of subgrade and pavement damage or traffic congestion and so on. Therefore, a reasonable and effective implementation of freeway reconstruction is the main task and pressing issues in the current and future period of freeway construction in order to provide good services for social and economic activities. Our country latest promulgated the "Freeway Reconstruction Design Rules"(JTG/TL11-2014) set forth requirements that traffic organization programs of reconstruction should be dynamic design.Based on the master of research results and combined with "Freeway Reconstruction Design Rules"(JTG/TL11-2014) and the "Road Maintenance Safe Work Practices"(JTGH30--2004), this paper analyzed the characteristics and applicability of reconstruction widened form, and defined the reconstruction work area of the basic freeway which is also rebulided. Relying on Beijing-Hong Kong and Macao Zhumadian to Xinyang section "four-lane to eight" freeway reconstruction project instance, this paper carried out Vissim simulation reliability studies and built the reasonable evaluation index and system with Vissim as simulation platform,at the same time carried traffic organization programs dynamic design against different traffic volume, carts rate and reconstruction work area closed to traffic in different modes.Research mainly achieved the following:(1)Divided reconstruction work section reasonaby to lay the foundation for the dynamic design of traffic organization programs;(2)Built reconstruction work area traffic organization programs more evaluation index system to provide a theoretical basis for the reconstruction work area traffic organization programs dynamic design of different traffic volume and carts rate;(3)Recalibrated the vissim expectations of the velocity distribution curve based on the operation area actual speed to improve the reliability of the simulation;(4)For the reconstruction work area of lane closure mode,research has identified a reasonable speed limits mode of work area and the ideal length value of the upstream transition zone in the different traffic volume and carts rate case; for the half of the road closure mode,by constructing theoretical model to determine the central median openings ideal length value of the different speed limits, different central median widths and different ultrahigh,in order to provide guidance opinions for the design under reconstruction work area traffic organization programs of various traffic conditions.The research results and "Freeway Reconstruction Design Rules"(JTGT 11--2014) proposed reconstruction traffic organization should be consistent with the requirements of dynamic design, which have reference value to traffic organization design of freeway reconstruction,and it is important to improve the service level of specific projects reconstruction area and ensure traffic safety.