Research On Optimizing Method Of Transportation Control For Roundabout With Low-carbon

In urban road traffic systems, Roundabout is the main traffic capacity bottlenecks of road capacity. Because of the insufficient traffic capacity of Roundabout, traffic congestion and jams is formed, thus it makes motor vehicles to produce great amount of exhaust pollution in an intersection region and makes urban traffic environment polluted. Setting signal control in the Roundabout is a practical approach for solving the traffic jams and serious environment pollution. Meanwhile the study also has a positive meaning on increasing traffic capacity of Roundabout and reducing the regional emissions.The study includes five aspects:1. The most important work is to establish the platform of motor vehicle testing system. By road test experiment, collecting the dates of different vehicle condition and emission data, and build the database based on the instantaneous emission rates of different vehicles and vehicle condition; then establish the VSP-based emission model which cover the vehicle condition and road gradient.2. By adopting a survey in the Roundabout areas of the structure, composition of ways, traffic flow of vehicles and the proportion of vehicles from different directions. And inputting the corresponding Roundabout parameters to the micro economic simulation software Paramics. And then build the topology chart of Satellite Square which is Roundabout traffic areas in Changchun., then settle the basic for the next step of integration of traffic simulation model so vehicle emission model can be performed to estimate emissions.3. Through the micro-simulation software, the second-by-second instantaneous speed, acceleration of single motor vehicle in the Roundabout can be obtained and Vehicle Specific Power can be calculated. Integration of traffic simulation model and vehicle emission model can be performed to calculate the instantaneous emission rates of different vehicle and total vehicle emissions in the Roundabout area. Also this work can be quantitatively assess the impacts on environment from vehicle emissions in the Roundabout area.4. According to Evaluating vehicle emissions of the roundabout area, for improving the quality of the environment, this work is to set traffic lights at each entrance of satellite square roundabout, and to transform satellite square roundabout. Then using Synchro signal timing optimization software to optimize the signals in the Roundabout, Integration of micro-emission model works out the total vehicle emissions in the satellite square which was transformed.5. By contrasting the exhaust emissions result between no signal control and signal control in the Roundabout area., it draws a conclusion that at the rush hour,setting the signal control can effectively reduce the regional vehicle emission. In contrast with before and after single transformation, under the same vehicle conditions, CO,HC,NOx emissions quantity respectively reduced 10.20%,12.22%,7.44%. Using of simulation software VISSIM to simulate the Satellite Square with signal control and output traffic flow parameters, compared with no signal control, vehicle average delay reduced by 56.50%,average parking speed decrease by 45.20%,saturation dropped by 41.50%. At the same time, average speed was also get a certain degree of improvement, makes the whole traffic flow more smoothly in this area.To sum up, in order to solve the problem of traffic jams and environment pollution situation in the Roundabout at the rush hour, by setting a signal control to reform a signal control in Roundabout, is a kind of economic and feasible way to reduce traffic congestion and improve the traffic environment situation. This paper studies how to improve low-carbon technology and energy savings in Roundabout traffic area and seeks a regional solution of the environment pollution in this specific area.