Bus rapid transit systems: a comparative assessment

There is renewed interest in many developing and developed countries in finding ways of providing efficient and effective public transport that does not come with a high price tag. An increasing number of nations are asking the question—what type of public transport system can deliver value for money? Although light rail has often been promoted as a popular ‘solution’, there has been progressively emerging an attractive alternative in the form of bus rapid transit (BRT). BRT is a system operating on its own right-of-way either as a full BRT with high quality interchanges, integrated smart card fare payment and efficient throughput of passengers alighting and boarding at bus stations; or as a system with some amount of dedicated right-of-way (light BRT) and lesser integration of service and fares. The notion that buses essentially operate in a constrained service environment under a mixed traffic regime and that trains have privileged dedicated right-of-way, is no longer the only sustainable and valid proposition. This paper evaluates the status of 44 BRT systems in operation throughout the world as a way of identifying the capability of moving substantial numbers of passengers, using infrastructure whose costs overall and per kilometre are extremely attractive. When ongoing lifecycle costs (operations and maintenance) are taken into account, the costs of providing high capacity integrated BRT systems are an attractive option in many contexts.     

Quality of institutions and private participation in transport infrastructure investment: Evidence from developing countries

In recent decades, owing to a series of public debt crises and constraints on government expenditure, infrastructure investment has dropped significantly in both developed and developing countries. To counterbalance this trend, Public–Private Partnerships (PPPs) schemes have been increasingly adopted. In this paper, we explore the determinants of the degree of private participation in transport infrastructure projects in a large sample of developing countries. By using a large sample of transport projects included in the World Bank Private Participation in Infrastructure Projects database, we document that greater participation by private parties in PPP contracts is associated with better institutions in terms of lower corruption, civil freedom, and a better regulatory framework.     

Transport infrastructure and long-run economic growth in OECD countries

This paper provides an empirical evaluation of the growth impact of public infrastructure in a panel of 18 OECD countries during 1870–2009. This study goes beyond the traditional analysis of growth accounting models by exploring the indirect effect of stock of core infrastructure on output growth through its impact on productivity. Constructing a long-run historical dataset on infrastructural capital formation spanning from 1870, estimated results show that growth in both labour productivity and total factor productivity are positively, but not substantially, influenced by growth in the stock of infrastructure. Furthermore, applying the system GMM technique (Generalised Method of Moments) revels that although rate of returns to investment in infrastructure exceed the private rate in OECD countries, it is not as high as positive externalities associated with investment in equipment and structure investment.     

The politics of collective public participation in transportation decision-making

Citizen involvement in transportation planning is typically modeled on a liberal democracy in which individuals express their preferences about a project. In this paper we present an analysis based on interviews with stakeholders whose involvement was grounded in a complementary model of public participation, one in which an organized community used collective action (instead of only individual expression), and worked both within and outside of the formal public involvement process to influence the design of an arterial highway in their neighborhood. This case reflects a commonplace context for public participation: residents opposing a highway expansion and the negative effects of heavy traffic in neighborhoods. The problem presented in this case is that the process for citizen involvement was not designed to fully utilize the community’s collective capacity. Three aspects of collective action—representation, the ability to shape a policy agenda, and methods of engagement—were contested in the public participation process. We argue that these conflicts around collective action in the public participation process exposed its “one-way communication,” and enabled a different kind of political process in which neighbors’ organizing was powerful and influenced decisions.     

Valuation of strategic options in public–private partnerships

This paper investigates the feasibility of and develops an economic valuation model for strategic options in Comprehensive Development Agreements (CDAs). A CDA is a form of public–private partnership whereby the right to price and collect revenues from toll roads is leased to a private entity for a long but finite period of time. In exchange, this provides local and state governments with a quick influx of cash and/or additional infrastructure. Uncertainty associated with such long-term leases is of substantial public concern. This paper examines five different strategic options, namely a buyout option, a conditional buyout option, a revenue-sharing option, and two types of minimum revenue guarantee options. The buyout option in particular could give the public sector additional control over the future use of leased facilities and address potential concerns regarding long-run uncertainty and possible unforeseen windfalls for the private sector. The paper’s contributions include the analysis, feasibility assessment and valuation of several strategic options, sensitivity analysis of the solutions, an economic consumer demand-based revenue model for purposes of cash flow simulation, and analysis of option price sensitivity to “moneyness”. The main conclusion is that strategic options can provide useful risk reduction, but generally have significant value relative to the lease itself. By scaling down payoffs, options could be realistically included in CDAs and other PPPs. For some parameter values, option values to the developer and public authority are offsetting, allowing for costless risk reduction.     

Adding a new station and a road link to a road–rail network in the presence of modal competition

In this paper we study the problem of locating a new station on an existing rail corridor and a new junction on an existing road network, and connecting them with a new road segment under a budget constraint. We consider three objective functions and the corresponding optimization problems, which are modeled by means of mixed integer non-linear programs. For small instances, the models can be solved directly by a standard solver. For large instances, an enumerative algorithm based on a discretization of the problem is proposed. Computational experiments show that the latter approach yields high quality solutions within short computing times.     

桥梁上部构造裂缝病害分析

对桥梁上部构造裂缝病害种类及成因进行分析。     

PKI认证模型的现状与发展

认证系统大多基于PKI基础,作者在系统的分析和比较成熟的基于PKI的认证系统的基础上，结合认证系统及其应用需求的发展研究，提出PKI认证的一种新的设计模型。     

PKI技术增强3G安全性研究

3G系统执行认证与密钥分配协议,在移动台和服务网络之间进行双向认证,在互相确认对方身份的基础上生成数据加密密钥CK和数据完整性密钥IK。3G安全体系的鉴权认证阶段是其薄弱环节,针对其缺陷,结合PKI技术,提出基于SSL握手协议的鉴权认证方案。在3G网络中加入认证中心及注册中心,用于验证用户身份、发放和恢复证书。针对无线终端特性,为服务器端使用的证书定义一个新的PKI证书格式———WTLS证书,并使用短时效证书SLC作为验证证书有效期的方案。该认证方案可以与3G现有安全模式并行,建议3G设置双模式认证方式来提高其安全强度。在无线终端侧实现了用户证书的存储管理,从而实现了加解密、数据完整性保护等各方面的功能,验证了基于SSL握手协议的鉴权认证方式是可行的。