Research On Fuel Economy Model Of Urban Road Based On Traffic Flow Status

With the accelerated process of urbanization in recent years, registered number of automobiles is in a rapid growth, which has made the transportation energy in the proportion of total energy consumption increase year by year. How to improve the fuel economy in urban road and construct the energy-saving environment protection, sustainable development transport systems become an increasingly pressing issue.From the traffic flow status, the fuel economy in urban road was systematically studied in this paper supported by the Natural Science Foundation of Heilongjiang Province, China(E200940). Fuel economy based on traffic flow status was further studied in order to providing the theoretical base for the establishment of evaluation system of urban road network fuel economy, road network planning, network transformation and traffic management which are based on fuel economy.Corresponding fuel economy models were established through analysis for fuel economy influence mechanism on condition that segment and intersection were regarded as the elementary unit on the basis of analyzing the existing fuel economy model and its theory. Model calibration and empirical research were done by using the fuel consumption and traffic flow data collected in field. The fuel economy models of route, OD pair and road network were established respectively, based on network unit fuel economy model and the route choice model on the basis of generalized travel cost function considering fuel economy. A partial road network in Harbin was selected as an example to analyze the network fuel economy and to verify the correctness and rationality.Based on the analysis of fuel consumption measurement methods, the Corrsys-Datron CDS-DFL1 fuel consumption measurement system was selected. The fuel consumption and traffic flow data observation program was designed from the determination of test methods, test line, the identification of test vehicle and driver, the setting of sampling interval and the test process. The filed observation and VISSIM simulation were used to get the fuel consumption and traffic flow data of roads and intersections under different traffic state and signal control program. The impact factors of roads and intersections fuel economy were analyzed from the traffic flow angle. Saturation, split and average speed on the impact of intersections fuel economy and saturation, average speed on the impact of road segments fuel economy were analyzed from the theoretical and experimental data point, respectively. The essence impact factors of road segments and intersections fuel economy were also explored in this paper. The results manifested that the essence impact factor of road segments fuel economy was saturation, and the essence impact factors of intersections fuel economy were saturation and split.On the basis of analyzing the limitations of the existing fuel economy estimation index, the economy fuel saturation was introduced to propose the road fuel economy index. The fuel economy models for different kinds of road segments and intersections were established based on saturation, saturation and split, respectively. The recommended grading standard value for road fuel economy was put forward. Finally, the above fuel economy models were applied to the partial road network in Harbin. The economy fuel saturation of different road segments and intersections in Harbin was calculated.Based on the study of the network unit-roads, intersections fuel economy models, the fuel economy, travel time (or delay) and travel time reliability (or delay fluctuations) were considered, and the generalized travel cost function of roads and intersections were defined, respectively. The cost indicators were processed to be a dimensionless quantity to eliminate the impact of the cost indicators of non-uniform dimension. The SUE (Stochastic User Equilibrium) model was established on the basis of generalized travel cost. In order to evaluate the road network fuel economy accurately, the path, OD (Origin Destination), network fuel economy was defined, respectively. The corresponding mathematical models were established by analyzing the relationship among the road, intersection, path, OD and road network fuel economy. The above models were applied to the fuel economy analysis for partial road network in Harbin, the results show that the models established in this paper are effective and appliciable.