A Tractor Handling Study

Agricultural tractors are relatively slow moving vehicles but a good steer response under all working conditions is generally required. This paper evaluates the effect of ground slope, axle load, ground speed, tyres and ground surface on yaw rate response to steer input.     

Maritime language: quest for simplicity

This brief paper examines some of the problems of interpretation of documents and procedures given in English faced by non-English seafarers, and suggests the use of 'controlled' English to simplify these problems.

' Speak English ', said the Eaglet, ' I don't know the meaning of half those long words, and what's more, I don't believe you do either. '

Alice's Adventures in Wonderland

Lewis Carroll     

Non-Contact Suspension and Propulsion Technology

As a result of extensive research and development in several countries, the technologies of magnetic suspension and linear electric drives are becoming available for transportation applications. The successful demonstration and operation of prototype vehicles has established the technical viability of these systems. Several urban transit or shuttle services, with magnetic suspension and/or linear motor propulsion are likely to be operational within 3-4 years. After the final stages ofdevelopment and rigorous testing, high speed systems are likely to be an option for intercity implementation by the end of the decade. This paper presents a report on the worldwide status of R&D and test programs of non-contact suspension and propulsion technology for guided ground transport.     

Emerging organizational values in shipping: Part 4. Decentralization—the redefinition of authority in shipping company organization

Decentralization is a major theme of organizational change in shipping. It is often seen as 'putting power back aboard ship'. However, the authors argue that this view is too simple. Decentralization poses fundamental questions about the entire management structure of the shipping company. The redistribution of authority necessary for decentralization is discussed in terms of the company organization structure.     

Dynamics of Pneumatic Tire Vehicles with Connected Suspension Systems

A vehicle model, with 10 degrees of freedom is used to investigate the skidding conditions of any wheel of the vehicle in motion. Equations for the load transfer and equations for the pneumatic tire spring and shock absorber are derived. Parameters such as gradual cornering, U-curve cornering, the wavy road surface of different wave lengths and cases of independent and connected suspension systems are inputs to the system. The tire calculated forces and their corresponding maximum resistance forces are the outputs of the systems. A connected suspension system is found to resist skidding better than the independent suspension system. The system is non-linear, and numerical solutions are obtained.     

A repeated cross-sectional evaluation of car ownership

This paper studies changes in the relationship between household car ownership and income by household type. Ordered response probit models of car ownership are estimated for a sample of households repeatedly at six time points to track the evolution of income elasticities of car ownership over time. Elasticities of car ownership are found to change over time, questioning the existence of a unique equilibrium point between demand and supply that is implicitly assumed in traditional cross-sectional discrete choice car ownership models. Moreover, different household types and households that underwent household type transitions showed differing patterns of change in elasticities. Observed trends in car ownership and income clearly show behavioral asymmetry where the elasticity of procuring an additional car is greater than that of disposing a car. This too shows the inadequacy of traditional cross-sectional models of car ownership which tend to predict symmetry in behavior. The study suggests the importance of incorporating dynamic trends into the forecasting process, which can be accomplished through the use of longitudinal data.     

Alternative systems for urban transport in India

This paper is in the context of studying alternative systems of urban transport in India to determine the costs and performance not only for public transport systems but also for the total transport scenario (i.e. for all vehicles) such that the economic costs are inclusive of costs of time (conservatively), accidents and pollution. In view of inherent deficiencies and delays associated with a traditional transport planning process and its implementation, the paper develops quick response land-use transport planning models for Indian cities to enable integrated, cost-efficient strategies to be evolved, recognizing that urban transport is a function of urban size, form, structure, socio-economic base, etc. A simple statistically significant demand model identified from a basis of appropriate data represents the recommended demand model for Indian cities. This model can be then conveniently used to project trip volume for any Indian city in a future year. A simple gravity model is used to generate the trip assignment for hypothesized city sizes, forms and structures. The results provide a fairly reasonable approximation for the major corridor trip volumes and lengths in the context of the transport requirement for the metropolitan cities in India in 2001 and 2011 A.D. The GOI Study Group arising from the investigations reported in this paper and the discounted cash-flow method of analysis made clear overall recommendations in February 1987 for cities of various populations.     

Policy innovations of the US intermodal surface transportation efficiency act and clean air act amendments

In combination, the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) and the Clean Air Act Amendments of 1990 (CAAA) are innovative and aggressive efforts to move US cities toward integrated transportation and air quality planning. Under these complementary laws, air quality has become a major national transportation goal. In areas with serious air pollution, air quality will be a major consideration in determining the future shape of urban transportation.This paper considers how the CAAA and ISTEA combine to provide an innovative national policy approach of interest to countries seeking to encourage sustainable development in urban centers. The CAAA mandates measurable and enforceable air quality targets. Nation-wide standards are set for acceptable levels of carbon monoxide, ground level ozone, and small particulates. ISTEA includes directions for transportation planners and decision-makers to follow to reach air quality and other goals — transportation planning must emphasize system efficiency, and for cities with severe air pollution, transportation projects are expected to contribute to cleaner air. Each urban area has flexibility in how it applies this framework to reflect its priorities and solve its problems. Strict federal sanctions provide incentives for compliance with both laws.Enactment of these laws has produced a period of transition and uncertainty as well as of challenge and opportunity for planners and elected officials. The next several years, the US will provide one national laboratory and over 100 different urban laboratories for innovative approaches to integrate transportation and environmental policies to resolve major urban problems.Abbreviations CAAA Clean Air Act Amendments of 1990 - CO Carbon monoxide - ECO Employee Commute Option - EPA US Environmental Protection Agency - HC Transportation hydrocarbons - I/M Inspections and maintenance program - ISTEA Intermodal Surface Transportation Efficiency Act of 1991 - MPO Metropolitan planning organizations - NO_x Nitrogen oxides - PPM Parts per million - PM₁₀ Small particulate matter - SIP State Implementation Plan - TIP Transportation Improvement Program - TCM Transportation control measures - VMT Vehicle miles traveled