Crosswind‐based optimization of multiple runway orientations

The runway orientation must satisfy the operational requirements of aircraft for landing and takeoff. Actually, the runway orientation is the result of compromises between the airport usability (wind coverage) and additional factors, such as available land, existing obstructions, topographic difficulties, flight path interference among runways and airports, noise pollution, and other environmental impacts. Therefore, the solution of a combination of acceptable runway orientations, which avoids excessive crosswinds at least 95% of the time, as well as the optimal orientation solution, is essential to conduct those compromises in the runway orientation analysis. The objective of this paper is to develop a computer model, named the optimization of multiple runway orientations model, which is capable of simultaneously providing a combination of acceptable runway orientations, changing the allowable crosswind limit flexibly, and determining the optimal orientations of multiple runway configurations. Instead of visual estimation or geometric computation, this paper presents an analytical method for wind coverage analysis. The model is mainly running in spreadsheet and Visual Basic for Applications (VBA). The numerical example and comparison show that the optimization of multiple runway orientations model is competitively accurate and convenient in comparison with previous ones. This paper presents an up‐to‐date model for the optimization of multiple runway orientations. By combining it with the geographic information system obstructions model, it can become an essential element of a future model for airport development cost minimization that combines airfield land use, earthwork volume, and cost estimation modules. Copyright © 2013 John Wiley & Sons, Ltd.     

The development of taiwan arterial traffic‐adaptive signal control system and its field test: A taiwan experience

This Taiwan traffic‐adaptive arterial signal control model borrowed its traffic flow framework mainly from a British traffic‐adaptive control model with a cyclic traffic progression function, i.e. SCOOT (Split Cycle Office Optimisation Technique). The new arterial control model can take into account delays of both major and minor streets and make real‐time signal timing decisions with optimal two‐way signal offsets, so as to create the best arterial signal operation performance. It has been developed to be an online real‐time software for both simulation testing and field validation. Through simulation, it was found that the performance when operating this newly developed real‐time arterial traffic‐adaptive model was significantly better than when using the optimal fixed‐time arterial timing plan. On the aspect of field testing, three signalized intersections located in East District, Tainan City, Taiwan were selected to be the test sites. Fairly good traffic control performance has been demonstrated in that it can effectively reduce travel delays of the control arterial as a whole. Additional discussions about how to combine travel delay and the total number of vehicle stops into a new control performance index have also been included to make the new traffic‐adaptive model more flexible and reasonable to meet the expectations of different driver groups in the arterial system.     

The value of travel time savings in freight transport: a meta-analysis

Transportation - The value of freight travel time savings (VFTTS) is a monetary value that is considered an important input into cost–benefit analysis and traffic forecasting. The VFTTS is...     

A revised branch‐and‐price algorithm for dial‐a‐ride problems with the consideration of time‐dependent travel cost

Developing demand responsive transit systems are important with regard to meeting the travel needs for elderly people. Although Dial‐a‐ride Problems (DARP) have been discussed for several decades, most researchers have worked to develop algorithms with low computational cost under the minimal total travel costs, and fewer studies have considered how changes in travel time might affect the vehicle routes and service sequences. Ignoring such variations in travel time when design vehicle routes and schedules might lead to the production of inefficient vehicle routes, as well as incorrect actual vehicle arrival times at the related nodes. The purpose of this paper is to construct a DARP formulation with consideration of time‐dependent travel times and utilizes the traffic simulation software, DynaTAIWAN, to simulate the real traffic conditions in order to obtain the time‐dependent travel time matrices. The branch‐and‐price approach is introduced for the time‐dependent DARP and tested by examining the sub‐network of Kaohsiung City, Taiwan. The numerical results reveal that the length of the time window can significantly affect the vehicle routes and quantitative measurements. As the length of the time window increases, the objective value and the number of vehicles will reduce significantly. However, the CPU time, the average pickup delay time, the average delivery delay time and the average actual ride time (ART)/direct ride time (DRT) will increase significantly as the length of the time window increases. Designing the vehicle routes to reduce operating costs and satisfy the requirements of customers is a difficult task, and a trade‐off must be made between these goals. Copyright © 2014 John Wiley & Sons, Ltd.     

Assessment of coastal zone issues in the Republic of Korea

Abstract

The physical characteristics of Korea have had a profound impact on the uses of the coastal zone that have, in turn, been determined by and reinforced the nation's economic development strategy. While coastal zone management in many developed economies is more heavily oriented toward environmental protection and the resolution of user conflicts, policies for coastal zone management in Korea have emphasized the role of coastal space and other resources for economic development and industrial needs. Increasing demand for land reclamation to provide ever‐increasing industrial sites and human settlements, traditional and future needs of the fishery, and concern for the environment have led to a vast array of competition and, finally, often to conflicts. The basic pattern of coastal zone use in Korea has changed from the linear expansion of coastal zone to integrated coastal uses. An increased number of critical coastal zone issues and interactions was reflected in the creation of new governance that dealt with coastal zone resources and environment.     

Excess Commuting: A Critical Review

Abstract

The stringent ship emission regulations under IMO's (International Maritime Organization) MARPOL Annex VI are a main driver to consider liquefied natural gas (LNG) as a ship fuel. Research into LNG as a marine fuel saw a strong growth in recent years, but no study has analyzed in a systematic way the level of convergence among the findings presented in the wide range of studies. In order to fill this gap, this paper seeks to perform a systematic review to synthesize the findings of 33 published studies on the use of LNG as a ship fuel. The aim is not only to obtain a much broader understanding of the current perspectives and challenges for applying LNG as a bunker for ship propulsion, but also to identify the gaps and weak points in the literature which could suggest future research. Moreover, given the output of the synthesis, the paper presents an extensive decision-making framework for shipowners when deciding on a fuel switch for their fleet from conventional oils to LNG in order to achieve a level of conceptual development beyond that attained in individual studies. In addition, the study also identifies the important role of ports in facilitating and encouraging the large-scale adoption of LNG in the maritime industry.     

Port Administrative Structure Change Worldwide: Its Implication for Restructuring Port Authorities in Taiwan

Abstract

This paper aims to review the evolution of the port authority’s role and recent changes in port administrative structure worldwide, and to discuss its implication for restructuring Taiwanese port authorities. It is found that the port authority is expected to play a proactive role in strategically managing overall port operations, and aggressively market its ports to port customers with a view to increasing cargo throughput and economic growth in its region. The change in the port authority’s role has driven a change in port administrative management structure worldwide. The proposed restructuring of port authorities in Taiwan is accompanied by some potential pitfalls. These include that the legislative framework of the programme is driven by political rather than professional concerns, and the port authority’s dual role as a regulator and as an operator at ports is against the principles of ‘separation of port administration (regulatory functions) and business management’ recently adopted worldwide. These pitfalls can impede the achievement of the objectives, including directing port authorities towards becoming independent commercially oriented entities. Therefore, this paper recommends that port corporatization approach will be a good alternative for restructuring Taiwanese port authorities.     

Driving Forces behind the Growth of Per‐capita Car Driving Distance in the UK, 1970–2000

Abstract

Although per‐capita car trip distance (measured in passenger‐km) and car driving distance (measured in vehicle‐km) in the UK have kept increasing, their growth rates slowed considerably in the 1990s when compared with the 1970s and 1980s. The paper investigates the main driving forces behind the changes in car trip and car driving distances, and it examines the determining factors for the slow down of growth in the 1990s on the basis of the analysis of data from the National Travel Survey (1975/76, 1989/91, 1992/94, 1995/97 and 1999/2001). In particular, it emphasizes the significance of changes in car ownership levels as a key driving force and attempts to separate this ‘car ownership effect’ from other effects. The log‐mean Divisia index decomposition method is applied to measure the relative contribution of each effect. Separate analyses are undertaken according to trip purpose. Other underlying causes, such as changes in fuel price and road capacity, are also examined.     

Recent developments in national and international freight transport models within Europe

The past decade has seen many new freight transport models for use in transport planning by public authorities. Some of these models have developed new concepts, such as logistics modules, inclusion of transshipments, storage and sourcing and the determination of shipment size. This paper provides a review of the European literature on freight transport models that operate at the national or international level and have been developed since 2004. The introduction of elements of logistics thinking is identified as a common theme in recently developed models, and further worked out. Furthermore, ideas on what might be the next key developments in freight transport modelling are presented.     

A network‐based model for estimating the market share of a new high‐speed rail system

This paper presents a novel application of static traffic assignment methods, but with a variable time value, for estimating the market share of high‐speed rail (HSR) in the northwest–southeast (NW–SE) corridor of Korea currently served by air, conventional rail and highway modes. The proposed model employs a time–space network structure to capture the interrelations among competing transportation modes, and to reflect their supply‐ and demand‐side constraints as well as interactions through properly formulated link‐node structures. The embedded cost function for each network link offers the flexibility for incorporating all associated factors, such as travel time and fare, in the model computation, and enables the use of a distribution rather than a constant to represent the time–value variation among all transportation mode users. To capture the value‐of‐time (VOT) of tripmakers along the target corridor realistically, this study has developed a calibration method with aggregate demand information and key system performance data from the NW–SE corridor.