A travel time reliability model of urban expressways with varying levels of service

Urban expressways usually experience several levels of service (LOS) because of the stop-and-go traffic flow caused by congestion. Moreover, multiple shock waves generate at different LOS interfaces. The dynamic of shock waves strongly influences the travel time reliability (TTR) of urban expressways. This study proposes a path TTR model that considers the dynamic of shock waves by using probability-based method to characterize the TTR of urban expressways with shock waves. Two model parameters are estimated, namely distribution of travel time (TT) per unit distance and travel distances in different LOS segments. Generalized extreme value distribution and generalized Pareto distribution are derived as distributions of TT per unit distance for six different LOS. Distribution parameters are estimated by using historical floating car data. Travel distances in different LOS segments are calculated based on shock wave theory. The range of TT along the path, which can help drivers arrange their trips, can be obtained from the TTR model. Finally, comparison is made among the proposed TTR model, generalized Pareto contrast model, which does not consider different LOS or existence of shock waves, and normal contrast model, which assumes TT per unit distance as normal distribution without considering shock wave. Results show that the proposed model achieves higher prediction accuracy and reduces the prediction range of TT. The conclusions can be further extended to TT prediction and assessment of measures to improve reliability of TT in a network.     

长江航道基本要素信息采集与服务数据交换技术*

数据交换规范是长江航道基本要素信息采集与服务的基础.根据长江数字航道建设规划项层设计要求,提出航道基本要素信息采集与服务数据交换平台架构,分析当前现有航道要素信息采集与服务终端数据交换的技术需求,制定适应于长江航道基本要素自动采集与服务数据交换规范化方案,并建立信息采集与服务终端测试平台,为下一步数字航道与智能航道工程建设提供技术支撑.     

Optimizing sustainable feeder bus operation considering realistic networks and heterogeneous demand

A mathematical model is developed to optimize social and fiscal sustainable operation of a feeder bus system considering realistic network and heterogeneous demand. The objective total profit is a nonlinear, mixed integer function, which is maximized by optimizing the number of stops, headway, and fare. The stops are located which maximize the ridership. The demand elasticity for the bus service is dependent on passengers' access distance, wait time, in‐vehicle time, and fare. An optimization algorithm is developed to search for the optimal solution that maximizes the profit. The modeling approach is applied to planning a bus transit system within Woodbridge, New Jersey. Copyright © 2011 John Wiley & Sons, Ltd.     

Relationships among service quality,corporate image,customer satisfaction,and behavioral intention for the elderly in high speed rail services

Since the Taiwan High Speed Rail operations, Taiwan's transportation market entered into a new era. Because of its competitive service of speed, convenience, environmental concerns and comfort, the High Speed Rail has not only made significant changes but has played a significant role in Taiwan's transportation. However, Taiwan now is an aging society. Due to the physical constraints among the elderly, demands to redesign the traffic system and maintain transportation safety are essential considerations. In the current market, Taiwan's transportation construction is facing fewer barriers; however, it must still improve, especially considering the health of the elderly. Thus, this study investigates elderly passengers' demands and further examined the relationships among service quality, corporate image, customer satisfaction, and behavioral intention. According to empirical analytical results based on structural equation modeling (N = 341), satisfaction directly affected travel behaviors, while service quality and corporate image played indirect roles. In addition, service quality plays a significant role on the effect of satisfaction. This study provides empirical evidence to indicate the quality of the accessible environment affects not only the effectiveness and efficiency of service quality, but also, the corporate image. The results provide valuable references for critically managing the elderly's usage of the high speed rail transportation service. Copyright © 2011 John Wiley & Sons, Ltd.     

基于服务质量差距模型的南宁出租车服务营销策略研究

文章采用城市出租车服务质量差距模型,结合南宁市出租车的服务现状,从乘客期望和实际感知的服务差距角度探讨影响城市出租车服务质量的因素,并从营销的角度提出改进策略.     

基于海洋多源数据聚融的公共信息服务平台建设研究

文中提出建设基于海洋多源数据聚融的公共信息服务平台,阐述了平台的体系架构、网络架构、技术架构、服务体系等设计要点及平台建设的关键元素为适应日益增长的航海保障提供优质服务．     

含裂纹船用气瓶安全评价及剩余寿命预测

针对船用气瓶使用过程中出现的疲劳失效问题,开展含裂纹气瓶安全评价及剩余寿命预测研究,通过疲劳裂纹扩展速率试验,得到疲劳裂纹扩展速率公式。对3种典型尺寸表面裂纹进行理论计算,获得船用气瓶安全评定结果和临界裂纹尺寸,并通过3种人工预制裂纹疲劳试验和安全评价验证理论公式的合理性。评定结果表明：当初始裂纹深度[a]≤1.5 mm,长度[2c]≤10 mm时,船用气瓶可安全使用至下一周期。     

基于Synchro的厦门市白鹭洲路信号协调控制的优化设计

在现有道路交通设施条件下,实现干道上信号协调控制能有效提高主干道的通行能力。以厦门市白鹭洲路为研究案例,根据该道路的几何结构特征和实际交通流特点,提出“分时段分方向、设置半周期时长”的干道信号协调控制方法,应用Synchro仿真软件建立基于原控制参数的干道信号协调控制系统;同时,在应用Synchro优化各个独立交叉口信号控制参数的基础上,建立了基于优化控制参数的信号协调控制系统。通过比较优化前后的干道信号协调控制系统的控制效果,仿真结果显示：在早高峰和晚高峰时段,交叉口延误分别降低11.3%和21.6%;干线延误分别降低8.2%和55.9%;路网总延误分别减少13.3%和22.0%。     

基于神经网络和支持向量机的大客车运行车速组合预测

为了降低单个预测方法的不确定性,综合神经网络和支持向量机两种学习型算法,基于二者的最优加权组合对大客车运行车速进行了预测.以二级公路上244个路段的平曲线半径和纵坡度等线形数据和实测车速为样本,分别应用BP神经网络、支持向量机、最优加权组合预测以及线性回归对大客车第85百分位运行车速进行了预测.选择均方根误差和判断系数为评价指标,对比结果表明,最优加权组合预测能够综合单个预测方法的信息,提高了预测精度.     

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本次论坛针对城市交通的发展需要,探讨了智能交通物联网和综合交通信息服务问题,认为智能交通物联网就是将技术实用、理念先进的物联网技术,融合各种先进的智能交通技术以及人工智能等技术,运用于交通管理、信息服务和车辆控制等智能交通领域,以达到人、车、路和环境之间的和谐统一,从而形成高效、准时、舒适、低碳的城市综合运输系统.在综合交通信息服务方面,强调服务内容的深刻性和个性化,以及服务模式的人性化、智能化.强调使综合交通物联网信息最大限度地与其他各类相关信息系统实现互联互通,进而催生新的应用和服务.