浅述过水侧石在天津临港经济区清河道道路设计中的应用

多年以来,我国的城市道路建设均使用城市地下雨水管道收集路面雨水,这种方法破坏了原有的雨水循环系统,产生了很多问题。在临港经济区清河道的道路设计中,因地制宜地设计了一种过水侧石,既不破坏原来的雨水循环系统,又极大地降低了工程量。详细介绍这种过水侧石在清河道道路设计中的应用。     

Optimal funding allocation strategies for safety improvements on urban intersections

Urban intersections crashes cause significant economic loss. The safety management process undertaken by most states in the United States is referred to as Highway Safety Improvement Program and consists of three standardized steps: (i) identification of critical crash locations, (ii) development of countermeasures, and (iii) resource allocation among identified crash locations. Often these three steps are undertaken independently, with limited detail of each step at the state planning agencies. The literature review underlines the importance of the third step, and the lack of sophisticated tools available to state planning agencies for leveraging information obtained from the first two steps. Further, non-strategic approaches and unavailability of methods for evaluating policies may lead to sub-optimal funding allocation. This paper overcomes these limitations and proposes multiple optimal resource allocation strategies for improvements at urban intersections that maximize safety benefits, under budget and policy constraints. Proposed policy measures based on benefits maximization (economic competitiveness), equitable allocation (equity), and relaxation of mutually exclusiveness (multiple alternatives at one location) produce significantly different alternative and fund allocation. The proposed models are applied to selected intersections in four counties of southeast Michigan. Results reinforce the applicability of the strategies/policies and tools developed in this paper for safety project funding allocation on critical urban intersections.     

无砟轨道胀板病害区段的自动化评估方法研究

CRTSⅡ型板式无砟轨道广泛应用于我国高速铁路中,在现场的服役过程中胀板病害是其性能劣化的最主要表现之一。对胀板病害特征及其形成原因作了简要分析,针对胀板病害区段,利用轨检数据分析了高低不平顺的时域波形特征,计算高低不平顺的时域特征值,并给出胀板区段自动化评估方法,建立高速铁路无砟轨道区段评估指标管理办法。通过算例对所提算法的适用性和准确性进行验证。结果表明:高温期胀板区段单块与连续轨道板病害表征为时域波形单峰与多峰特征;区段标准差这一指标可以作为描述胀板结构性病害的依据;利用胀板病害区段自动化评估算法实现了胀板区段的定量化评估。     

北京市域快线主要技术指标研究

分析现阶段北京轨道交通发展现状,提出研究市域轨道交通主要技术指标的必要性。北京市域快线具有服务半径大、旅行时间长、运行速度快、服务水平高等特点,把市域快线特点需求归纳为需求层、服务层、系统层3个层次,提出北京市域快线最高速度、旅行速度、行车间隔、车辆定员、车辆参数等指标。     

基于运量的国民经济效益网络计算法

通过对现行国民经济效益计算方法的研究,运用交通分配理论论证了现行计算方法中运量分析存在的问题。依据交通分配理论和消费者剩余理论,将交通建设项目吸引区内整个路网作为研究对象,建立了基于运量的国民经济效益网络计算法。实例计算表明该方法的有效性。     

Measuring the influence of bus service quality on the perception of users

Encouraging the use of public transport is a key policy goal in many countries. Therefore, public transport should offer the level of quality that accommodates the demands of current users, and importantly, the desires of potential users. This study investigates the influence of the perceived quality of bus service on the perception of both current and potential users. The study draws upon data from 512 questionnaires distributed across Belfast City in the UK. The study utilises a binary logistic regression model to quantify the relationships between the perceived quality of 29 bus indicators (independent) and the perceptions of users towards the overall bus service (dependent). Eleven significant indicators are reported to have significant influence on the perception of users. These indicators are utilised to propose scenarios for optimising the quality of bus service with the perceptions of current and potential users.     

The relationship between urban street networks and private motorized trips at the city level

There are factors that impact car usage in urban areas, such as density, diversity and design, but there have been few studies that examine the relationship between street network factors and car usage at the city level (macro level). This paper focuses on this relationship by introducing urban street network variables, such as blocks per area, nodes per block and length of roads and motorways, as independent variables and the percentage of daily trips by private motorized modes as the dependent variable. The street network in this study includes interconnecting lines and points that present streets, roads, motorways, intersections and blocks. The strength of the relationship in this study is found using multiple linear regression. The findings of this research indicate that an increase in car usage is correlated with an increasing number of blocks per area, number of nodes per block and length of motorways. In addition, because the urban street network is the result of macro-scale planning decisions, considering this relationship can lead to better planning decisions.     

关键绩效指标在集装箱码头设备管理中的应用

关键绩效指标(KPI)的应用,可为集装箱码头设备管理提供管理依据。介绍了关键绩效指标的含义、数据来源及其计算方法。实际应用后,证明是一种切实可行的管理方法和工具。     

Analysis of the economic and social parameters of the Three-Wheeler Taxi service in Sri Lanka

Sri Lanka has an extensive Three-Wheeler Taxi service comprised of around 300,000 vehicles. These vehicles, which first made an entry to Sri Lanka’s roads in the early 1980s, account for around 15% of the active motor vehicle fleet at present. Three-Wheelers Taxis also account for around 6% of the passenger kilometres. These vehicles are mostly individually operated with some owned by the operator and others hired on a monthly or daily basis. The industry is unregulated with vehicle registration and driving licenses being the only instruments of regulation. Fares are unregulated. However, most operators belong to associations which are loose collections of operators found in a given locality. These associations impose a degree of self regulation with respect to fares. They also tend to demonstrate oligapolistic behaviour.The paper is based on a survey of 200 operators and 100 passengers from a Divisional Secretariat area in Colombo District. The survey covered a number of details pertaining to ownership, management and fare structures, as well as opinions on the service attributes by users. The survey also covered perceptions of operators to determine the social, economic and transport implications of the services provided. Details were also obtained on the profiles of the operators and their expectations.The paper provides the results of the analysis of this data and draws a number of conclusions on the economics of the industry as well as the social aspects associated with it. It also discusses the characteristics of the users of these three wheelers as well as their typical use. The analysis also investigates complementarily of service provision between three wheelers as an access mode to buses and railways. This analysis has been used to develop an understanding of the manner in which the industry has grown over the last two decades and how it is being operated today. It also identifies areas wherein the industry has become inefficient and assesses the degree of over pricing that exists due to this. The data also helps to determine the relationship between unemployment and provision of self-employed transport services.The paper concludes with a synopsis of the profile of the industry and its role within the wider transport sector and with respect to ownership. It also discusses the positive and negative impacts of the lack of regulation on the industry.     

Competition in Brazilian bus and coach services - The results of recent competitive tendering processes

This paper analyses the terms and the results of a sample of some recent Brazilian bidding processes for the concession of public passenger transport services: namely, urban and metropolitan bus or regional coach services. The analysis is based on selected issues relating to competitiveness and upon the legal framework that applies in this sector. It was concluded that, given the lack of bidding processes for concessions in the bus and coach sector in Brazil, the fact that some bidding processes have been carried out should be considered a sign of progress. However, these auctions have not necessarily prioritised competitiveness, since many barriers to entry into the systems were imposed by the bidding terms. Future competitive tendering processes should seek to abide by stricter principles of competitiveness, if they wish to avoid the entire effort expended on conducting such processes serving only to mask nothing more than formal obedience to the law and to discredit the bidding process in the eyes of Brazilian citizens.