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Open research questions in Transportation Planning and Optimization

129 unresolved questions extracted from the limitations and future-work sections of 942 Transportation Planning and Optimization papers in our library. Each links back to the study that raised it.

What the literature leaves open

  • The high costs of implementing and operating light rail transit systems. The potential for light rail transit to have higher operating costs than bus transit. The need for careful planning and evaluation to ensure the success of light rail transit systems.

    A Dark Side to Light Rail? The Experience of Three New Transit Systems · 1985 · DOI

  • The paper notes that it is too early to draw definitive conclusions about the effectiveness of light rail transit. The paper also notes that the lack of detailed before-and-after ridership surveys makes it difficult to evaluate the impact of light rail transit on ridership. The paper acknowledges that the experience of the three cities may not be representative of other cities.

    A Dark Side to Light Rail? The Experience of Three New Transit Systems · 1985 · DOI

  • The gap between the economic and political perspectives on transit policymaking. The lack of consideration for the economic consequences of transit policy.

    Management Vs. Political Perspectives on Transit Policymaking · 1985 · DOI

  • The paper notes that the potential savings from operational changes are small. The paper also notes that the implementation of staggering school hours and multiple tripping may be limited by opposition from parents and teachers.

    Cost‐saving options in school transport: a Tasmanian case study · 1982 · DOI

  • The paper suggests that future research could consider the potential for home education through telecommunications. The paper also suggests that future research could consider the implementation of staggering school hours and multiple tripping in other contexts.

    Cost‐saving options in school transport: a Tasmanian case study · 1982 · DOI

  • Further analysis of the implications of new telecommunications technology on travel time. Investigation of the stability of travel time budgets in the long term.

    The law of constant travel time and trip-rates · 1982 · DOI

  • The lack of a satisfactory explanation for the law of constant travel time and trip-rates. The lack of statistical evidence from areas and countries where time budget surveys do not exist.

    The law of constant travel time and trip-rates · 1982 · DOI

  • The study is limited by the availability of data, which may not be comprehensive. The analysis is also limited to the 1970s, and may not be representative of current transport policy.

    An evaluation of transport policy in the 1970's · 1982 · DOI

  • The study identifies a gap in the effectiveness of transport policy in achieving its objectives. The gap is particularly significant in terms of environmental degradation and energy consumption.

    An evaluation of transport policy in the 1970's · 1982 · DOI

  • The gap between systems theory and practical concerns of organization development. The need to consider human well-being and social sciences in organizational development.

    Human factors in transport research · 1981 · DOI

  • There is a lack of understanding of the cost structures of publicly-provided urban bus transportation. Prior research has focused on privately-owned bus systems, leaving a gap in knowledge for publicly-owned systems. The study highlights the need for further research on the cost structures of urban bus systems.

    ESTIMATION OF THE ELASTICITIES OF FACTOR SUBSTITUTION IN URBAN BUS TRANSPORTATION: A COST FUNCTION APPROACH* · 1981 · DOI

  • The study identifies a gap in the understanding of the distribution of transit subsidy benefits and costs among income classes. The study notes that previous justifications for transit subsidy growth were based on the belief that the poor would benefit, but the actual distribution of benefits was unknown.

    Equity in Transit Finance: Distribution of Transit Subsidy Benefits and Costs Among Income Classes · 1981 · DOI

  • Further consideration of issues associated with defining an operational level of optimal capacity in the presence of different individual responses to crowding is needed.

    The Economics of Congestion: a Comment · 1981 · DOI

  • There has been little recognition that preferences for crowds vary and that crowding in some cases generates positive effects. Earlier work did not make an analytical distinction between subjective and objective effects of congestion.

    The Economics of Congestion: a Comment · 1981 · DOI

  • Future research could focus on the development of a true PRT system. Future research could explore the implementation of the proposed transit system.

    Personal Rapid Transit · 1980 · DOI

  • The gap is the lack of a transit system that can provide demand-responsive service. The gap is the limited expansion of national transit ridership or carrying capacity despite significant investment.

    Personal Rapid Transit · 1980 · DOI

  • There is little consensus as to how social scientists interested in a normative theory of the public space economy should proceed. Conventional welfare theory appears to be inadequate for addressing issues of social welfare and its distribution over people and over space.

    Welfare Theory, Public Goods, and Public Facility Location · 1979 · DOI

  • The complexity of the social system involved in public transportation policy making. The need to consider the implementation process in decision making. The potential for counter-intuitive effects of governmental action.

    Public transportation policy making in France as an implementation problem · 1979 · DOI

  • The paper suggests that future research could focus on developing new categories of benefits that could be costed out for attribution to urban mass transit. The paper also suggests that future research could explore the implementation of a pricing solution that takes into account the social costs of driving.

    The Politics of Economics in Transit Planning · 1978 · DOI

  • The paper identifies a gap in the economic approach to urban mass transit policy, which is subject to criticism on grounds of empirical inadequacy, bias, and political unfeasibility. The gap is that the economic approach does not consider the distribution of benefits among the population.

    The Politics of Economics in Transit Planning · 1978 · DOI

  • The paper identifies a gap in the understanding of the relationship between gasoline prices and urban bus ridership. The study aims to fill this gap by estimating the gasoline price elasticity of bus ridership and the bus system size elasticity of bus rides.

    The impact of gasoline prices on urban bus ridership · 1978 · DOI

  • There is a lack of importance assigned to environmental factors in transport operations. Assessing environmental implications of transport operations is difficult.

    Urban Transport and the Environment · 1977 · DOI

  • The complexity of modeling household choice of transport alternatives. The need to separate the effects of changes in parking costs and changes in running costs on modal choice. The challenge of estimating the microelasticity of mode choice with respect to parking costs.

    Estimation and specification of the effects of parking costs on urban transport mode choice · 1977 · DOI

  • The lack of consideration of parking costs in traditional modal choice studies. The need for a distinct parking cost variable to separate the effects of changes in parking costs and changes in running costs on modal choice.

    Estimation and specification of the effects of parking costs on urban transport mode choice · 1977 · DOI

  • The study suggests extending the analysis to consider the variable population size of a city. The research recommends exploring the division of the whole population into urban and non-urban sectors. The paper proposes examining the impact of non-urban sectors on the optimal allocation of land.

    Cost-benefit analysis and the second best land use for transportation · 1977 · DOI

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129 open questions have been extracted from the limitations and future-work passages of 942 Transportation Planning and Optimization papers in our library. Each one below links back to the study that raised it, so you can read the original claim in context.

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