Advanced Materials Research Vols. 243-249

Abstract: In order to study dynamic response of rough road surface resulting from different speeds and loads under a certain roughness for purpose of effective enhancement pertinence for structural design of an asphalt pavement and extension of its service life, displacement meters, stress meters and strain meters are embedded at different structural layers on the rough road surface to monitor the dynamic responses of AC pavement. The result shows that roughness can dramatically increase response on an asphalt road surface resulting from load and speed.

Abstract: Through analyzing the factors affecting passengers’ path-choice, the corresponding principles and rules of the ticket income distribution are put forward and the new model of the Urban Rail Transit Network in Beijing is set up in the paper. Through the deformation of the urban rail transit and the simplification of the lines, the topology of the urban rail transit lines is abstracted into an undirected connection graph. Breadth-priority optimization algorithm is applied to search the effective paths between the OD and the flow-matching ratio is acquired by calculating based on multi-factor matching algorithm, in which many relevant numerical examples are analyzed to verify the feasibility of the dual-ratio method and to summarize the characteristics of the project.

Abstract: With the expansion of port handling capacity and economic benefit, large mountains highway traffic volume are aggregated to and transported by ports, and large increment of traffic volume of mountains highways connected with the port occurred. Based on studying characteristics of port transportation and mountainous highway traffic network, mountains highway traffic volume transferred by ports is analysed, and corresponding analysis model of passenger and goods volume of entering and leaving port is put forward. Firstly, choosing ports which mainly effect mountains highway volume; secondly, conllecting and studying category of goods, characteristic of passenger, throughput of passenger and goods, and development program of these ports in past years; thirdly, investigating goods category, throughput, space, and some other useful data of these ports at the present. Characteristics of waterway goods transportation is studied and spatial distribution of passenger, goods volume between different ports is estimated, and mountain highway traffic volume transferred by ports is forecasted. The method proposed in this paper is applied successfully in practical engineerings, and provides reference for engineering research.

Abstract: The relationship between ramp length and traffic flow speed (TFS) was studied based on analyzing the design elements of geometry alignment for interchange. After analyzing the process of vehicle running in the ramp, the speed change process was divided into four forms, namely, one deceleration and acceleration process, one deceleration process, one acceleration process and more than one deceleration and acceleration process, and then the relationship between the ramp length and TFS was established respectively. Through an example of the HeDa Interchange of Heilongjiang Province, it showed that although the differences of alignment units of ramps can result in various speeds and specific expressions of relationship between ramp length and TFS. However, all of these relations can be expressed by homologous nonlinear function.

Abstract: This paper proposes coupling the Pipes car-following model with the GM model to formulate a new car-following model that can generate consistent separation distances between the leading and following vehicles. First, an example is given to show that the GM car-following model can lead to different separation distances at the same steady speed. Secondly, a new model is formulated by coupling the Pipes model with the GM model and it is shown that the only meaningful attractor of the new model is one producing consistent separation distances at the same steady speed. Furthermore, the relationship of those macroscopic traffic flow quantities inherent in the new car-following model has also been investigated. In the steady state, the resulting speed-density relationship is exactly the same as one derived from the Pipes model. In the dynamic case, the derived speed-density relationship is a partial differential equation. Numerical experiments are carried out to show that the new car-following model can generate consistent separation distances between the leading and following vehicles.

Abstract: Six methods to determine axial pile capacity directly based on piezocone penetration test (CPTU) data are presented and evaluated. Analyses and evaluation were conducted on three types piles that were failed during pile load testing. The CPT methods, as well as the CPTU methods, were used to estimate the load carrying capacities of the investigated piles (Qp ). Pile load test were used to determine the measured load carrying capacities (Qm). The pile capacities determined using the different methods were compared with the measured pile capacities obtained from the pile load tests. Two criteria were selected as bases of evaluation: the best fit line for Qp versus Qm and the arithmetic mean and standard deviation for the ratio Qp /Qm. Results of the analyses showed that the best methods for determining pile capacity are the CPTU methods.

Abstract: This paper presents a simple identifying method of bike group ,then takes bicycle groups of signalized intersection as the research object, investigations and video cameras are carried out at two signalized intersections in Beijing and Tianjin city. For the data analysis,by using K-means cluster analysis method ,this paper selects three criterions which are the average speed of bicycle group,the width of bicycle group and the length of bicycle group. Based on three indexes , the passing stage of the bicycle groups at two signalized intersections of Beijing city and Tianjin city are divided into three stages :the first stage for bicycle group gradually spreading ,the second stage for expanding ,the third stage for gradually shrinking.The research on the passing stage of bicycle group starting and running through the intersection at the signalized intersection are useful for determining the capacity of vehicles with the impact of bicycle , and for calculating the signal timing of bicycle under the mixed traffic flow condition at signalized intersection.

Abstract: Vehicle to pedestrian/bicycle accidents account for a large proportion of traffic accidents in China. In order to study the characteristics of vehicle to pedestrian/bicycle conflicts, 50 taxis are chosen as the test vehicles. A field-test was conducted using video driver recorder in Beijing for one year. A large amount of traffic conflict and accident data was collected in real driving environment. Considering the factors including conflict type, conflict time, conflict location, traffic control and conflict speed etc., the traffic conflict characteristics of vehicle to pedestrian/bicycle were analyzed. The results might contribute to the road safety management, road design and accident prevention technology.

Abstract: This paper takes commuters’ daily travel as research object to build model of travel choice which contains departure time and travel route based on Prospect Theory. Choosing the time of arriving destination as reference point, commuter will choose the time at which he/she can obtain the maximum value as departure time, then establishes choice model of departure time. Using Bayesian Theory to update and adjust route’s forecasting travel time in light of traffic information provided by Advanced Traveler Information Systems (ATIS) and travelers’ previous experience information. Gets decision weighting function after having analyzed traveler’s individual subjective probability which is about the possible result for route choice, then obtains the expression of travel route’s prospect value and gets route choice model. Finally, by designing a network to analyze the dynamic choice model, and achieves expected effect.

Abstract: Manual count method is adopted during the statistics of the intersection traffic volume of Dongshan Midway in Huainan. According to the statistics, basic characteristics of traffic volume, such as composition, direction and number, are obtained. Based on the research, the problems existed in the intersection are analyzed, and feasible measures for optimization design of intersection are put forward, in order to ensure the safety of pedestrian crossing and increase the traffic capacity and service level efficiently.