Patterns and projections of technical development in freeway surveillance and control in the U.S.A.

This paper explores the historical trends in freeway traffic management technology in the U.S., and the most likely projections for the coming two decades. First, existing computer‐supervised freeway surveillance and control techniques are reviewed with particular emphasis on the scientific and technological landmarks which has led to the evolution of these techniques. Next, the major underlying trends which bear on the future of automated freeway surveillance and control are identified. Finally, extrapolative projections are made to determine the most likely future of this technology. The paper concludes with implications for the issues of meeting short‐term transportation needs of urban areas through more efficient use of existing transportation facilities.     

Redefinition of roles and responsibilities in U.S. transportation

Major shifts in U.S. Federal transportation policy are occurring which are realigning the roles and responsibilities of the Federal, State and local governments, and the private sector. These shifts include a decentralization of control to State and local governments, a larger role for the private sector, and reduced emphasis on construction of new facilities and more on rehabilitation and utilization of existing facilities. Although some reaction to these changes is already apparent, it is unclear at this time what the effect will be on improving the efficiency and effectiveness of transportation systems.     

Lead emission rates from gasoline engines—a legislative and in‐use emission rate study of U.K. and U.S. to 1990

Concern for reduction in air‐borne lead emission from passenger cars is focussed on both the legislative and practical steps in reducing lead in gasoline. The historical trends and projections to 1990 of present U.S. and U.K. policies are examined in terms of a baseline passenger car lead emission rate, g.km^‐1. It is likely that should the U.K. adopt a lead‐free petrol the decrease in lead emissions will only partially parallel the present U.S. experience from a start‐up date typically post 1990. The U.S. gasoline pool philosophy has permitted lead levels in gasoline to remain high; a pitfall which the U.K./EEC should avoid.     

Effect of mass on multimodal fuel consumption in moving people and freight in the U.S.

The United States transportation sector consumes 5 billion barrels of petroleum annually to move people and freight around the country by car, truck, train, ship and aircraft, emitting significant greenhouse gases in the process. Making the transportation system more sustainable by reducing these emissions and increasing the efficiency of this multimodal system can be achieved through several vehicle-centric strategies. We focus here on one of these strategies – reducing vehicle mass – and on collecting and developing a set of physics-based expressions to describe the effect of vehicle mass reduction on fuel consumption across transportation modes in the U.S. These expressions allow analysts to estimate fuel savings resulting from vehicle mass reductions (termed fuel reduction value, FRV), across modes, without resorting to specialized software or extensive modeling efforts, and to evaluate greenhouse gas emission and cost implications of these fuel savings. We describe how FRV differs from fuel intensity (FI) and how to properly use both of these metrics, and we provide a method to adjust FI based on mass changes and FRV. Based on this work, we estimate that a 10% vehicle mass reduction (assuming constant payload mass) results in a 2% improvement in fuel consumption for trains and light, medium, and heavy trucks, 4% for buses, and 7% for aircraft. When a 10% vehicle mass reduction is offset by an increase in an equivalent mass of payload, fuel intensity (fuel used per unit mass of payload) increases from 6% to 23%, with the largest increase being for aircraft.     

Own and cross-price elasticities of demand for domestic flights and intercity trains in the U.S.

In 2009, the U.S. Federal Government announced its plan to invest in the expansion of the passenger rail system, instead of adding to the freeway or aviation systems. On the other hand, environmental studies show that passenger rails have a lower polluting impact than flights or cars. In order to evaluate whether consumers would switch from flights to trains and use the new rail system, this paper estimates the own and cross-price elasticities of demand for domestic flights and passenger trains using the methodology described in Berry (1994). Specifically, the changes in demand for domestic flights and trains with respect to their prices are evaluated. The static model in this study suggests that the substitutability between these two modes of transport is minimal, in other words, travelers will to change their choices is very small given the configuration of the transportation system when the notice was made. In particular, train trips are substituted more easily.     

Transit performance evaluation in the U.S.A.

Performance of transit agencies in the United States improved during the 1980s. At the beginning of the decade, Americans had become disenchanted with transit; legislation was passed that required agencies to report performance and accept regular audits. Theory underlying these policies is examined in four components: dimensions for policy objectives, indicators, information systems and incentives. Three programs are examined: federal triennial reviews that monitor compliance with planning and grant requirements, California performance audits that analyze goals and track performance on five indicators and the Los Angeles program that encourages improvement by offering incentive payments for better-than-average performance. The California audits have been the most successful.     

Car-deficit households: determinants and implications for household travel in the U.S.

Transportation - In the U.S., households with less than one car per driver (auto-deficit households) are more than twice as common as zero-vehicle households. Yet we know very little about these...     

Regulatory policy and economies of scale in the U.S. intercity bus industry

After nearly a half century of federal and state regulation, the U.S. intercity bus industry is the subject of proposals which would drastically reduce the extent of governmental control over fare setting, service abandonment, and market entry. An essential requirement for understanding how these regulatory changes might affect the industry is knowing the extent to which economies of scale are present in the provision of intercity bus services. This paper reports on the analysis of economies of scale for both Class I firms and for Class II and III firms. The results show nearly constant returns to scale beyond very low output levels but very strong dependence on the mix of charter and regular-route service provided.     

Transport studies research in U.K. universities

British universities have entered a period of crisis. The outward manifestation of the current malady has appeared as a general cut-back in university spending. Until two or three years ago, most universities looked forward to a modest growth in activity. This has now been changed and the expectations of growth have been replaced by the reality of consolidation and modest decline. However, the universities are not alone in their dilemma. The general downturn in economic prosperity has left few institutions unscathed. Most universities, both in Britain and abroad, have therefore been forced to review their expectations and their ongoing commitments in teaching and research. The review of university activity goes much deeper than the immediate problems of finance. The current soul-searching has been sparked off by the crisis of finance, but has roots which go much deeper and touch on the very fundamentals of university education itself. In a sense, one is witnessing a belated form of public accountability: what is the purpose of a university; should its subjects be demonstrably relevant (both in themselves, as well as in their capacity to prepare students for a career); should universities engage in research and, if so, should it complement their teaching functions or be additional to it? These, and many other issues, are currently being discussed, and it is specifically with reference to their role in the field of transport research that this paper is addressed.     

Economies in U.S. demand responsive transit

This paper develops a neoclassical cost function for demand responsive transit (DRT) system and uses it to test the economies of scale hypothesis. The results show economies of scale and further show that the economies can be explained by speed, local and state subsidies, utilization of seating capacity, fleet utilization and an increase in the number of professionals. Comparison of DRT and bus transit results identifies patterns in policy variables whose effects on cost are the same across modes.     

Gender differences in commuting travel in the U.S.: interactive effects of race/ethnicity and household structure

Transportation - This research investigates the interactive effects of the household structure and race/ethnicity on gender differences in commuting travel in the United States. Existing research...