Effects Of Work Zones On Road Network Capacity

With the continuous intensification of traffic congestion in large and medium cities in China and traffic infrastructure construction continues to accelerate,constructions that have to close lanes have a great negative impact on traffic,because work zone usually becomes a bottleneck on urban road.Since road network capacity is limited,it's especially important to study whether the traffic can match the overlapping and centralized construction in a specific area under a certain traffic demand.Firstly,the thesis introduces the diversity of the definition of road network capacity,and defines the definition of road network capacity in this thesis.By comparing and analyzing the three methods of researching road network capacity,and considering the practicality and extensibility of the model,this paper proposes the traffic assignment simulation method based on TransCAD to calculate the road network capacity.Secondly,based on the discussion of work zones' traffic characteristics,the paper analyzes the factors of the road capacity of work zones.Those factors are calculated and simulated by using mathematic model and Vissim under different work zones Conditions,and the capacity reduction coefficient of each factor is obtained.Thirdly,this thesis combines the road capacity and the calculation of road network capacity.By the use of open source maps,programming and software simulation techniques,the paper calculates the road network capacity without construction and under construction in a certain area of Wuhan,and then evaluates the degree of construction in this area.Based on instance calculations,this thesis puts forward some suggestions for this area.By using the methods presented in this paper,it's easy to calculate the road capacity of work zones.In addition,the calculating method of road network capacity can illustrate the influence of work zones on the traffic because of its expansion and visualization.We can predict the traffic impact of a construction,and then provide the decision reference for the construction plan of the city.