Defining and understanding trip chaining behaviour

Trip chaining is a phenomenon that we know exists but rarely investigate. This could be attributed to either the difficulty in defining trip chains, extracting such information from travel diary surveys, the difficulty in analysing all the possible trip chain types, or all of the above. Household travel diary surveys provide a wealth of information on the travel patterns of individuals and households. Since such surveys collect all information related to travel undertaken, in theory it should be possible to extract trip-chaining characteristics of travel from them. Due to the difficulty in establishing and analysing all of the possible trip chain types, the majority of research on trip chaining has appeared to focus on work travel only. However, work related travel in many cities does not represent the majority of activities undertaken and, for some age groups, does not represent any travel at all. This paper begins by reviewing existing research in the field of trip chaining. In particular, investigations into the definitions of trip chaining, the defined typologies of trip chains and the research questions that have been addressed are explored. This review of previous research into trip chaining facilitates the following tasks: the identification of the most useful questions to be addressed by this research; defining trip chaining and associated typologies and defining data structures to extract trip chaining information from the household travel surveys conducted in metropolitan Adelaide, South Australia. The definition and typology developed in our research was then used to extract trip-chaining information from the household travel diary survey (MAHTS99) conducted in Adelaide in 1999. The extracted trip chaining information was then used to investigate trip-chaining behaviour by households. The paper reports the results of this analysis and concludes with a summary of the findings and recommendations for further investigations.     

Problems faced by the shipping industry in raising capital in the securities markets

This papers examines the reasons for the shipping industry's general failure to exploit the enormous capital raising potential offered by the world's major security markets. The basic reason put forward is one of joint ignorance and lack a of communication. On the one hand shipping perceives the market as being unsympathetic to its requierments. On the other hand, the Stock market assess it as a minor activity and this is combined with a presumption of industrial instability. An analysis of recent initial public offering of equaity options in shipping highlights the inadequacy of companies who have ventured that way. In particular it is pointed out that shipping companies who embark on such a course must not forget that equaity is, at one end the same time, the cheapest and the most expensive money which they can raise. There is a further underlying problem for the industry, which is that market capital raising neccessiates the loss of personal control.     

Cutting vehicle emissions with regenerative braking

This paper presents an analysis of vehicle regenerative braking systems as a quick and relatively easy means of achieving higher overall fuel efficiency and lowering carbon emissions. The system involves the installation of an additional electric motor/generator in parallel to the vehicle’s internal combustion engine and is used in conjunction with a DCDC converter and ultracapacitor. The system is used to recapture the energy lost in vehicle braking, significantly reducing a vehicle’s overall energy consumption and lowering vehicle emissions. Experimentally-based evidence is collected and compared for two sample vehicles to deduce the potential fuel and emissions saving.     

A multi-layer scenario analysis for sustainable international transport

This article considers the development of the international transport sector based on four globalization scenarios. These four images of the future transportation market are constructed at three different levels (global, European and Dutch). The possible consequences of these scenarios are mapped out not only by key aspects such as modal split and spatial organization but also by providing empirical insights into expected transport flows for both passenger and freight transport in 2020 based on data from 1995.     

Model coastal zone statute

Abstract

This model statute sets out a mechanism for the management of the coastal zone by the coastal states. It provides a possible state response to the Coastal Zone Management Act of 1972. The authors recognize that most states presently have some form of management or legal control over their coastal zone, and the model statute has been written with the intention that all or parts of it could be adapted to the wide variety of state regulatory schemes with the aim of providing unitary management to the valuable resource of the coastal zone.     

The trade‐off between efficiency,effectiveness, and social feasibility of regulating road transport externalities

This paper discusses the tension between the theory and practice of the regulation of road transport externalities from the viewpoint of the trade‐off between efficiency, effectiveness and the social feasibility of regulation. Various possible types of regulatory instruments, subdivided into ‘direct’ demand management, ‘indirect’ demand management and ‘supply side’ oriented policies, are evaluated qualitatively according to these criteria. Attention is then directed towards the trade‐off between efficiency, effectiveness and feasibility within the field of ‘direct’ demand regulation of road transport.     

Application of probability theory to marne project appraisal

The importance of specifying and quantifying the project risks in the investment decision process cannot be overemphasized. Even more so in the context of marine project appraisal, since the shiping markets are characterized by extreme volatility and high cyclicality. The use of probability theory in investment decisions is reviewed and applications are derived for marine projects. The paper focuses on the use of Monte Carlo simulation to determine the mean and variance of the input variables. Within the Monte Carlo framework three alternative methods are used for the construction of probability distributions; the scaled halves of a normal distribution, two unscaled parts of a normal distribution and finally use of altenative distributions, such as beta, gamma and chi-square. An alternative methodology is also drawn from the literature, namely the Pearson-Turkey three point approximation, to contrast with the Monte Carlo method.     

The influence of route guidance advice on route choice in urban networks

The paper begins by reviewing what is known about route choice processes and notes the mismatch between this knowledge and the route choice assumptions embedded in the most widely used assignment models. Empirical evidence on the influence of route guidance advice on route choice is reviewed and, despite its limited nature, is seen to suggest that users are reluctant to follow advice unless they find it convincing and that, the more familiar they are with the network, the less likely they are to accept advice. Typically only a small minority of journeys are made in total compliance with advice.Results from an interactive route choice simulator (IGOR) are summarised and are seen to reveal that compliance depends on the extent to which the advice is corroborated by other factors, on the drivers' familiarity with the network and on the quality of advice previously received. It is noted that the IGOR results are in a form which would enable response models to be calibrated.Recent approaches to the modelling of route choice in the context of guidance are discussed. Some are seen to make simplifying assumptions which must limit the relevance of their results; most make no allowance for the fact that drivers are unlikely to comply with all advice and several are not able to represent the benefits which guidance might bring in the context of sporadic congestion or incidents.As an alternative, a two phase model comprising a medium term strategic equilibrium and a day-specific simulation with explicit representation of driver response is proposed.Updated and extended from an earlier version published in theProceedings of the Japan Society of Civil Engineers (JSCE No 425/IV-4, 1991-1).     

Safer ships, cleaner seas

P&I clubs, as shipowners' organizations providing liability insurance for the same shipowners have a particularly vital role to play in exerting peer group pressure and raising standards of safety. Solutions are, however, never as simple as one might wish; this article explores the tensions and constraints within which P&I clubs operate, analyses where they are best equipped to support the Donaldson initiative and points out that there is an inherent conflict between liberal modern society and the desire for discipline on the high seas.