Welcome to the April 2013 issue of Transport, which provides a selection of papers from around the world on two of our transport networks: highways and railways. The topics cover performance, design and maintenance of a network. In today's current economic climate it is particularly important that engineers contribute to providing value for money to the global transportation network.
The first paper by Odoki et al. (2013) describes the development of the World's Bank's highway development and management model HDM-4 for use by the Department of Transport (DfT) at strategic level. This development involved the adaption and calibration of HDM-4 to model the pavement performance and road user effects in England, linking to the existing database system. A trial strategy analysis was also undertaken to quantify long-term maintenance requirements. The paper demonstrates that HDM-4 can be established as a comprehensive decision support tool for use by the DfT, which enables them to carry out medium- to long-term planning of maintenance expenditure. It also provides a framework to ensure that maintenance funds are distributed equitably among local authorities and that value for money for the taxpayer is achieved.
Continuing the theme of pavement maintenance, the paper by Meneses et al. (2013) from Portugal presents the development and implementation of a multi-objective decision-aid tool for pavement management. The tool provides a new approach by using this multi-objective deterministic optimisation model. It was tested using data from Oliveira do Hospital's pavement management system, whose road network has a total length of 65·8 km. It allows pavement management systems to become interactive decision aided tools and provides engineers with answers to ‘what-if' questions.
Continuing with the road networks but moving to China, Tu et al. (2013) describes research undertaken on vulnerability analysis. The functionality of the network is disrupted when incidents occur reducing the level of service to users. Using a vulnerability index, from the field of telecommunications, network links are formed to determine the disaster-resistant ability of the network and to calculate the criticality index of these links. Identifying these critical links is important for planning; demonstrated with the results of a trial network. Data from the Shanghai freeway were also tested. The paper describes how the network vulnerability was evaluated and how construction of new links will lessen the network's future vulnerability.
Moving from mainland China to Taiwan the paper by Li and Lai (2013) looks specifically at transportation and land-use development through an empirical link. Globally, and over time, transport and land use have developed a close relationship, shaping the urban form of transport and land-use connections. A literature review was undertaken and previous research on 35 major cities around the world updated. Using empirical analysis the study develops both the quantitative and qualitative definitions of these connections.
Finally, back to the UK and another transport system, the railway. The paper by Banimahd et al. (2013) presents a study on the geotechnical performance of high speed railway tracks using a three-dimensional, finite-element method. As design and maintenance of the track is often strongly based on empirical relationships and simple models a three-dimensional model can provide an appropriate tool for the simulation of railways tracks in different conditions. The paper describes how the model developed the items that were simulated, for example, track displacement and ballast vibrations, and provides the results of the analysis. Track maintenance was also studied in terms of vibration and stress levels in the ballast and subgrade resulting in the classification of a series of maintenance levels. Using the outcome for this dynamic finite-element analysis a design method is proposed that aims to minimise track and ballast maintenance thus providing value for money.
I hope you find the papers in this issue informative. The Editorial Advisory Panel are always looking for new papers that cover the many aspects of transportation and I would encourage you to consider writing a paper yourself to further the dissemination of engineering knowledge and talent around the world. The Panel looks forward to hearing from you.
