| Currently the Urban roads are usually in construction or renovation status to satisfy the demand for rapid expansion of modern cities.In these periods,road construction or renovation not only can bring environment pollution,but also make the traffic congestion in the construction areas.Meanwhile,it is easy to cause the traffic delay and capacity reduction,which has a great impact on the travel of people.As we know,the road capacity has a close relationship with the time and space resources,especial the intersections.Therefore,this research intends to optimize the time and space resources to guarantee the smoothness of traffic flow in the construction period.In this way,the conflict between the traffic operation and road construction can be eased effectively,because the road capacity has a close relationship with the space-time resources.Firstly,the factors of urban road intersection,as well as indicators of space-time resources optimal allocation are analyzed by field research and literature review.Then the detailed flow of intersection signal timing is determined based on this.Next,the capacity of construction road is analyzed by focusing on the research of the factors of road capacity and the characteristics of road space-time resources.After the definition of the affected scope of construction is determined,the circle layer extrapolation method and the service level method are taken as the research method by comparing the model of affected scope of construction.Finally,the specific process for the determination method of affected scope of construction is introduced in this research.Secondly,the model of lane function division for spatial resource optimization is proposed,based on concluding the basic theory of traffic flow in construction areas.The proposed model considers the balance index of lanes and traffic flow ratio.Meanwhile,the multi-objective signal timing model with time resource optimization is proposed,which considers the capacity,delay time and the number of stops according to the saturation of the lanes.Based on these two theoretical models,the specific process and calculation method of time and space resources optimal allocation at urban road intersections during the construction period is determined,which will have a certain reference to guide the optimal allocation of time and space resources at urban road intersections.Finally,this research uses the construction project of Urumqi north expressway corridor as the example.By introducing the background and general situation of the construction project in detail,this research analyzes the traffic conditions of roads and intersections,as well as applies the Aidaroe simulation software to evaluate the operation of intersection.Combining the lane functional division model and multi-object signal timing optimization model,the optimized space-time resource configuration scheme is concluded.Through the comparative analysis of the simulation,the results show that the optimized intersection capacity had a substantial increasement,the average delay and average stop number of vehicles at intersection also reduce significantly.In addition,the results confirm that the proposed the space-time resource optimization model has suitability and effectiveness for the construction urban road,which can ease the traffic congestion at intersection obviously during the construction period. |
