Applied Mechanics and Materials Vols. 253-255

Abstract: Carbon monoxide has a significant impact on human health, and a special attention should be given in the tunnel management. But the existing tunnel design standard about carbon monoxide concentration is mainly for rural highway especially for expressway, there is no urban road tunnel carbon monoxide concentration control criteria promulgated in China up to now. By analyze the character of human blood carboxy hemoglobin concentration which expose in different environment concentration of carbon monoxide according to a certain time, and take carboxyhaemoglobin that accounts for 2.0 percent in the hemoglobin as the carbon monoxide concentration control threshold for the model development to establish the basis for carbon monoxide concentration of both pedestrian and vehicle mixed tunnel and vehicle only tunnel with different lengths, put forwards the length limit of pedestrian and vehicle mixed tunnel and the recommend criteria for carbon monoxide concentration control of urban tunnels. The result of the study can has a support for urban tunnels design and management decision making especially in ventilation.

Abstract: The optimization model is framed with a goal to minimize overall consumption of travel time for passengers. A variety of constrains are considered, including time, capacity, stop number, profit and so on. According to the features of the model, the hill-climbing algorithm is adopted to obtain the initial solution, which reduces the time of optimization. Meanwhile, direct order encoding method, namely node method, is introduced for encoding, construct a Hybrid Genetic Algorithm for the solution. The results show that adapter value is more steady and the model result is preferable when the variation rate is increased while the number of iteration is decreased.

Abstract: A midblock U-turn facility is often provided on multilane divided highway to manage direct right turn maneuvers from main stream. Mid block U-turn facility provides a safe turn for drivers who want to change their directions. As the number of vehicles in major road increase, the driver who wants to do U-turn faces more difficulties to find a suitable gap. This study is conducted to find a critical gap acceptance and empirical relationship between U-turning delay and volume on near-side traffic lane at midblock U-turn facility in multilane divided highway. Methodology of the study was observation and in order to have a precise data, video recording technique was used. Greenshields gap acceptance method was used to analyse the data. Through the collected data, a total of 916 rejected gaps and 810 accepted gaps were used for analyzing and results show that critical gap acceptance is 3.5 sec. Meanwhile, there is an empirical relationship between delay of U-turning and volume on nearside traffic lane on major road.

Abstract: By designing scientific, efficient, safe and comfortable bus stations, the design of harmonious bus station is actually coordinating and harmonizing the relationship among people, bus, station and environment. This paper aims to investigate and analyze the bus station by the concept of harmony, and finds the basis of design and summarizes the principle of harmonious bus station design.

Abstract: Roundabouts have since become increasingly common. Statistically, roundabouts are safer for drivers and pedestrians than both traffic circles and traditional intersections. However, in the actual life, now roundabout faces the challenge that the traffic flow exceeds the limit. In order to decrease the construction cost and maximize the benefits, in accordance with the analysis of the roundabout capacity and traffic signal control, the author put forward a self-suitable red light adjustment scheme based on BP neural network. At last, integrating the roundabout traffic management system actually investigated, selecting the data to do the test to prove the validity of the mentioned scheme.

Abstract: The evaluation of the municipal transportation efficiency is an issue that cannot be wholly and sufficiently analyzed quantitatively, for it, involves many factors, some of which are just beyond quantitative analysis. Based on AHP (Analytical Hierarchy Process), the author suggests an evaluation index system in which different weight is allocated to each index according to its effect on municipal transportation. Combining AHP and different weight allocation, the present paper proposes a fuzzy evaluation (appraisal) system of municipal transportation efficiency and presents an example analysis targeting at the removal and settlement of the barriers and problems that hamper the improvement of city transportation efficiency.

Abstract: This paper proposes a game-based model to conduct the issue of road congestion pricing. The ride comfort of travel modes, e.g., cars or buses, is introduced into the travel cost function of the traditional bottleneck model. Furthermore, based on different travel cost functions of various travel modes, the Nash equilibriums are achieved among the government and various travelers. The results can be employed to describe internality and externality of traffic system respectively. Finally, numerical examples are presented. The findings of our work indicate a relationship between the government’s goal and the charge rate and that the emergence of ride comfort obviously is a key determinant of travelers’ behavior.

Abstract: This paper started from the perspective of the implementation effect of public transportation priority development strategy, and studied on the evaluation of urban public transit operational level of service, then whether the strategy was well put into effect could be examined. On the basis of the existing research on the evaluation index of public transit operational level of service, this paper carried out a microscopic level of service evaluation on public transportation priority strategy. Then the effect of the strategy was analyzed from the level of passengers’ satisfaction. At last, the result of this strategy was examined by the increasing of proportion of the public transportation travelers. Finally, according to the establishment of the index system, it was analyzed respectively from the two aspects of objective and subjective with the combination of AHP and passenger satisfaction survey. Then the grade of urban public transit operational level of service could be obtained.

Abstract: The Beijing Subway system carries about 8 million passengers per day in 2012, and the congestions caused by large passenger volume has become a major issue in transit stations especially transfer ones. In order to suppress the congestion to an acceptable level, an indicator reflecting transit station service level is urgently needed. However, previous researches mainly focus on the passenger density of certain areas, such as stairs and walking corridors. This paper aims to propose a composite indicator reflecting the service level of a whole transit station. Filed investigation of several transfer stations was conducted during peak commuting period, in order to find out the usual congestion points of each passenger flow line. According to investigation results, Platform stair, Exit AGM (Automatic Gate Machine), Platform and Corridor entrance were chosen as key nodes to reflect transit station service level. And the weight of each key node was decided by the average passenger density ratio, based on simulation experiment of SHD station. Finally, the service level of SHD station was evaluated with fuzzy comprehensive evaluation.

Abstract: In order to reduce the negative impact of urban traffic air pollution, this paper firstly analyzes the relationship between urban traffic air pollution and vehicle speed, after providing the relationship model, the paper establishes a comprehensive pricing model of urban traffic air pollution based on bi-level programming, the model considers the traffic air pollution pricing, and includes the factors of congestion pricing, bus fee, pricing revenue redistribution on improvement of public transport services and the expansion of road capacity. The case study shows that the implementation of comprehensive pricing of urban traffic air pollution can reduce traffic pollution and unreasonable traffic flow, which is conducive to the sustainable development of the city.