13 research outputs found

    Road Capacity and the Allocation of Time

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    Additional highway capacity, by increasing travel speed, affects the individual share of time within a 24-hour budget allocated to various activities (time spent at and traveling to home, shop, work and other). Some activities will be undertaken more, others less. This paper extends previous research that identified and quantified induced demand in terms of vehicle miles traveled, by considering what type of demand is induced and which activities are consequently reduced, using the 1990 and 1995 Nationwide Personal Transportation Survey and Federal Highway Administration highway statistics data. While total travel times have not seen any significant change between the years 1990 and 1995, there is a significant change in activity durations. Further, as a result of additional capacity, workers spend less time traveling. Workers also spend more time at home and other activities and less at work and shop. Non-workers, in contrast, travel more, and spend more time shopping and at home, but less time at other activities. This points out the differences in discretionary and non-discretionary activities for workers and non-workers. It also suggests that there are real gains from capacity in people's lives, at least in the short term, as it is time, and not VMT, that individuals base decisions on.Time Use, Travel Behavior, Activity Patterns, Roadway Capacity, Induced Demand.

    Inter-technology Effects in Intelligent Transportation Systems

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    This project examines the expected benefits of varying combinations of ITS applications: Freeway Service Patrol, Changeable Message Signs, and Ramp Metering. The research analyzes the simulated results of a stylized network in a microscopic traffic simulator. The traffic network includes parallel roadways, ramp meters and changeable message signs. We have tested these technologies in various combinations. We measure effectiveness as consumers' surplus and define a measure of inter-technology economies. In brief, it is found that additional technologies are sub-additive, and more benefits come from each technology in isolation than when it is bundled with other technologies.Transportation System Management, Inter-technology Economies, Freeway Service Patrol, Changeable Message Signs, Ramp Metering, Intelligent Transportation Systems, Evaluation ,

    Whence Induced Demand: How Access Affects Activity

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    Additional highway capacity, by increasing travel speed, affects the individual share of time within a 24-hour budget allocated to various activities (time spent at and traveling to home, shop, work and other), some activities will be undertaken more, others less. This paper extends previous research that identified and quantified induced demand in terms of vehicle miles traveled, by considering questions of what type of demand is induced and which activities are consequently reduced. This paper uses the 1990 and 1995 Nationwide Personal Transportation Survey and Federal Highway Administration highway statistics data. While total travel times have not seen any significant change between the years 1990 and 1995, there is a significant change in activity durations. Further, as a result of additional capacity, workers spend less time traveling. Workers also spend more time at home and other activities and less at work and shop. Non-workers, in contrast, travel more, and spend more time shopping and at home, but less time at other activities. This points out the differences in discretionary and non-discretionary activities for workers and non-workers. It also suggests that there are real gains from capacity in people's lives, at least in the short term, as it is time, and not VMT, that individuals base decisions on.Highway capacity--United States, Trip generation--United States, Traffic flow--United States, Travel demand

    Road Capacity and the Allocation of Time

    No full text
    Additional highway capacity, by increasing travel speed, affects the individual share of time within a 24-hour budget allocated to various activities (time spent at and traveling to home, shop, work and other). Some activities will be undertaken more, others less. This paper extends previous research that identified and quantified induced demand in terms of vehicle miles traveled, by considering what type of demand is induced and which activities are consequently reduced, using the 1990 and 1995 Nationwide Personal Transportation Survey and Federal Highway Administration highway statistics data. While total travel times have not seen any significant change between the years 1990 and 1995, there is a significant change in activity durations. Further, as a result of additional capacity, workers spend less time traveling. Workers also spend more time at home and other activities and less at work and shop. Non-workers, in contrast, travel more, and spend more time shopping and at home, but less time at other activities. This points out the differences in discretionary and non-discretionary activities for workers and non-workers. It also suggests that there are real gains from capacity in people's lives, at least in the short term, as it is time, and not VMT, that individuals base decisions on

    Inter-Technology Effects in Intelligent Transportation Systems

    No full text
    The expected benefits of varying combinations of intelligent transportation system applications, such as freeway service patrol, changeable message signs, and ramp metering, were examined. The research analyzed the simulated results of a stylized network in a microscopic traffic simulator. The traffic network included parallel roadways, ramp meters, and changeable message signs. These technologies were tested in various combinations. The effectivenesses were determined, and a measure of intertechnology economies was defined. In brief, additional technologies were found to be subadditive, and more benefits came from each technology in isolation than from the bundling of each with other technologies
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