Accessibility appraisal of land-use/transport policy strategies: More than just adding up travel-time savings

We examine the accessibility benefits associated with some land-use policy strategies for the Netherlands that anticipate on expected climate change. A disaggregate logsum accessibility measure using the Dutch national land-use/transport interaction model TIGRIS XL is used to compute changes in consumer surplus. The measure provides an elegant and convenient solution to measure the full accessibility benefits from land-use and/or transport policies, when discrete choice travel-demand models are available that already produce logsums. It accounts for both changes in generalised transport costs and changes in destination utility, and is thus capable of providing the accessibility benefits from changes in the distribution of activities, due to transport or land-use policies. The case study shows that logsum accessibility benefits from land-use policy strategies can be quite large compared to investment programmes for road and public transport infrastructure, largely due to changes in trip production and destination utility, which are not measured in the standard rule-of-half benefit measure.     

Using structural equations modeling to unravel the influence of land use patterns on travel behavior of workers in Montreal

This paper addresses the relations between travel behavior and land use patterns using a Structural Equations Modeling (SEM) framework. The proposed model structure draws on two earlier models developed for Lisbon and Seattle which show significant effects of land use patterns on travel behavior. The travel behavior variables included here are multifaceted including commuting distance, car ownership, the amount of mobility by mode (car, transit and non-motorized modes), both in terms of total kilometers travelled and number of trips. The model also includes a travel scheduling variable, which is the total time spent between the first and last trips to reflect daily constraints in time allocation and travel.The modeled land use variables measure the levels of urban concentration and density, diversity, both in terms of types of uses and the mix between jobs and inhabitants/residents, the transport supply levels, transit and road infrastructure, and accessibility indicators. The land use patterns are described both at the residence and employment zones of each individual included in the model by using a factor analysis technique as a data reduction and multicollinearity elimination technique. In order to explicitly account for self selection bias the land use variables are explicitly modeled as functions of socioeconomic attributes of individuals and their households.The results obtained show that people with different socioeconomic characteristics tend to work and live in places of substantially different urban environments. But besides these socioeconomic self-selection effects, land use variables significantly affect travel behavior. More precisely the effects of land use are in great part passed thru variables describing long term decisions like commuting distance, and car ownership. These results point to similar conclusions from the models developed for Lisbon and Seattle and thus give weight to the use of land use policies as tools for changing travel behavior.     

Determinants of Indian sub-continent officer–seafarer retention in the shipping industry

The retention of officer–seafarers within the international shipping industry is a difficult problem facing shipping and ship management companies. One strategic option open to all companies that should improve overall retention is to seek to become an employer of choice by providing an intellectual capital environment attractive to officer–seafarers. This is investigated through a survey of officer–seafarers covering areas where ship management can exercise some control over their working conditions. These cover recognition by their employer and commensurate rewards, organizational culture and structure and building relationships with external parties. Experienced Indian sub-continent officer–seafarers were the sample population resulting in more than 200 valid completions. These were analysed using correlation and regression. Although all hypotheses were in the predicted direction, only four passed the significance test: long-term career prospects, a smooth and fair recruitment process, a better relationship with maritime authorities and an employee-friendly organizational culture. Stepwise regression indicated that only organizational culture had a significant positive effect on intention to remain a seafarer. The items in the organizational culture construct accord with recommendations from the literature on becoming an employer of choice and improving employee retention, providing guidance for attracting and retaining officers.     

Do mergers and alliances influence European shipping and port competition?

In Europe, ports are confronted with a closer integration in the maritime and shipping industries. The co-operation agreements can take several forms such as alliances and mergers among shipping lines, conferences, involvement of shipping companies in terminal management, and extending interests in inland transport of shipping companies. In this paper we give a brief overview of these different types of agreement and we examine the consequences of this evolution of the market structures in which ports and shipping companies have to operate. More specifically, attention goes to the competitive position of the port in this new environment. It is clear that the role of the port and the port authorities has to be redefined to guarantee that it remains a fully fledged player in this fast evolving integrated market.     

Semi-Active Attitude and Vibration Control

The paper discusses the attitude and vibration control of a passenger car on the basis of a full vehicle model. The analysis presented consists of two parts: (I) The introduction of a newly developed semi-active anti-roll/pitch system, (ii) An example of an actively suspended full vehicle model using a simple control strategy to improve ride comfort. The attitude control using semi-actively generated compensation forces prevents the car from rolling in curves and pitching during braking or accelerating. The strength of the system is the small energy consumption. The performance of the combination of both attitude and vibration control can compete with a fully active suspension system.     

Structural design of process decks for floating production, storage and offloading units

This work analyzes the influence of ship motion and deformation on the structural design of decks to support production plants in floating production, storage and offloading units (FPSOs). These decks are space frames with lengths ranging from 30 to 100 mr, with a variable number of rigid supports linked to the ship hull. The deck and ship hull are modeled together for naval and structural analysis. A global, coupled analysis is performed considering the deck and ship structures; sea loads are evaluated by means of probabilistic methods.     

Numerical Optimization of the Linear Dynamic Behaviour of Commercial Vehicles

The demands upon the dynamic behaviour of a vehicle can be stated as an optimization problem. The optimum solution is calculated using an iterative optimization algorithm. Scaling the problem by non-linear transformations reduces the number of iterations. Lagrange multipliers provide useful information about the sensitivity of the optimum with respect to changes of the constraints. The analysis of the dynamic behaviour is performed in the frequency domain. New structural variants are calculated using system synthesis. As an example, the engine, cab and wheel suspension systems of a tractor/semi-trailer have been optimized all together.     

Regularity and irreversibility of weekly travel behavior

Dynamic characteristics of travel behavior are analyzed in this paper using weekly travel diaries from two waves of panel surveys conducted six months apart. An analysis of activity engagement indicates the presence of significant regularity in weekly activity participation between the two waves. The analysis also shows a general lack of association between regularity in activity participation and change in person and household attributes, suggesting the presence of behavioral inertia or response lags. It is further shown that observed trip rates do not exhibit patterns that would be observed if travel behavior had no response lag and no history dependence. The results point to the needs for models that are capable of representing these aspects of travel behavior.