Research On Problems Concerning Urban Road Traffic

In this paper, we study some problems on urban road traffic, we try to configure the trafficlights to make the waiting time of vehicles minimally at intersections. Our preconditions are thatthe traffic flows are balanced, left-hand bend is forbidden, and the road-net is rectangular.Each intersection in the net is not isolated, the intersections are interactional. First, we thinkabout the synchronization of the adjacent intersections, found an optimal model that minimizethe average waiting time of the vehicles by defining the non-synchronism degree and the syn-chronous rate. Because the model is very complex, we can not give the result in theory, we givethe numerical result.The thesis is organized as follows:1)Studying only one intersection. First,we define the expedite, jam and synchronous rate ofintersection. Secondly, we give the essential and sufficient conditions of jam as given the inputtingtraffic flows of one intersection.Thirdly, we found two models of maximize the synchronous rateand minimize the average waiting time of the vehicles.At last, we give the numerical result.2)Studying the artery of serval intersections. In this paper, we only consider the traffic flowsin the artery, don't consider other traffic flows. First, we give the essential and sufficient conditionsfor the throughway to realize two-direction signal through, i.e. 'green wave project'. Secondly, forthose artery that the green wave project can not be realized, we give an optimal signal lampsconfigure by which the average waiting time of the vehicles through the way will be the least.Thirdly,we give the result of the model in theory in the simple conditions. At last,we give thenumerical result in the commonly conditions.3)Studying the united modulating signal lamps of the area.First, for one intersection, we givethe relation of inputting flows and outputting flows. Secondly, founding the united optimal modelof the contiguous intersections.Thirdly, because the model is very complex, we can not give theresult in theory, we devise a iterative way to resolve the model.At last,validate the validity and theconvergence of the iterative way by numerical examples.The main innovations in this paper as follows: 1)We define the synchronous rate of the adjacent intersections, so the description is moreclear and the model is more rational.2)We consider the synchronization of the adjacent intersections, that is more actual relativeto isolating the intersection.3)When optimizing the area,the intersections is divide to two styles, we found a iterativeway to gain the numerical and prove the iterative way is convergence.In this paper, we consider the traffic flows is symmetrical and the left-hand bend is forbidden,but the method in this paper is not limitative. It can resolve more commonly things. Because oftime limited, we can not study it ulteriorly.