摘要 :
This report examines the benefits of high-occupancy vehicle (HOV) lanes in threemajor freeway corridors in Houston, Texas: the Katy (I-10), Northwest (US 290), North (I-45) Freeways. The analyses described in this report used eigh...
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This report examines the benefits of high-occupancy vehicle (HOV) lanes in threemajor freeway corridors in Houston, Texas: the Katy (I-10), Northwest (US 290), North (I-45) Freeways. The analyses described in this report used eight months of travel time data (April through November 1994) available through Houston's automatic vehicle identification (AVI) traffic monitoring system. The travel time data were used to quantify travel time savings and reliability benefits of the HOV lanes relative to the freeway general-purpose lanes. The travel time data were also used to calibrate a macroscopic freeway simulation model for comparing an HOV lane alternative to other transportation improvements. Various measures of effectiveness, like person delay, fuel consumption, and mobile source emissions, were used to compare alternative improvements.
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This study analyzed data from a stated preference survey of Houston travelers faced with numerous mode choices, including value pricing options. The study: (a) examined the possibility of using a genetic algorithm to estimate mode...
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This study analyzed data from a stated preference survey of Houston travelers faced with numerous mode choices, including value pricing options. The study: (a) examined the possibility of using a genetic algorithm to estimate mode choice models while removing the need of making the IIA assumption, (b) estimated nested logit models, (c) attempted to estimate random parameter logit models, and (d) estimated numerous multinomial logit models. After comparing different specifications and optimization techniques (namely the genetic algorithm and Newton-Raphson method in the econometric software, Limited Dependent LIMDEP) the multinomial logit model estimation using LIMDEP was found to be more efficient because of easy estimation and a much lower time requirement for estimation. Hence a multinomial logit model was used for estimating the values of travel time savings (VTTS) and the penalty for changing travel schedule for different groups of travelers. The values estimated for the penalty for changing travel schedule were not statistically significant and were therefore not used. The values estimated for travel time savings were significant and comparable to those obtained in previous studies.
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The daily commute to a job is a cost of working. Workers may share stories about the extent or rigors of their commute, or they may enjoy the time with reading, music, or drive-time radio personalities. For any trip, many factors ...
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The daily commute to a job is a cost of working. Workers may share stories about the extent or rigors of their commute, or they may enjoy the time with reading, music, or drive-time radio personalities. For any trip, many factors contribute to a travelers choice of mode and route. Travel costs are estimated as value of time (VOT) and value of travel time savings (VTTS), estimates that seek to quantify both the tangible and intangible aspects of travel. Research into the proper methodologies and uses of data continue to evolve, but despite these uncertainties, VOT and VTTS are measures critical for transportation planners when developing cost-benefit analyses of projects, congestion pricing policies, or information about the likelihood of diverting travelers from single-occupant vehicles to alternative modes.
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摘要 :
The purpose of this study was to determine the potential travel times and paths of the postulated activated groundwater beneath the facility and to examine the fate and transport of this activated groundwater.'
摘要 :
The purpose of this study was to determine the potential travel times and paths of the postulated activated groundwater beneath the facility and to examine the fate and transport of this activated groundwater.'
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The 4 papers in the report deal with the following areas: travel time prediction and information availability in commuter behavior dynamics; nonlinear utility in time and cost of trips: disaggregate results from on ordinal methodo...
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The 4 papers in the report deal with the following areas: travel time prediction and information availability in commuter behavior dynamics; nonlinear utility in time and cost of trips: disaggregate results from on ordinal methodology; a method for estimating long-term changes in time-of-day travel demand; discrete/continuous analysis of commuters' route and departure time choices.
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Incidents account for a large portion of all congestion and a need clearly exists for tools to predict and estimate incident effects. This study examined (1) congestion back propagation to estimate the length of the queue and trav...
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Incidents account for a large portion of all congestion and a need clearly exists for tools to predict and estimate incident effects. This study examined (1) congestion back propagation to estimate the length of the queue and travel time from upstream locations to the incident location and (2) queue dissipation. Shockwave analysis, queuing theory, and cellular automata were initially considered. Literature indicated that shockwave analysis and queuing theory underestimate freeway travel time under some conditions. A cellular automata simulation model for I-66 eastbound between US 29 and I-495 was developed. This model requires inputs of incident location, day, time, and estimates of duration, lane closures and timing, and driver re-routing by ramp. The model provides estimates of travel times every 0.2 mile upstream of the incident at every minute after the start of the incident and allows for the determination of queue length over time. It was designed to be used from the beginning of the incident and performed well for normal conditions and incidents, but additional calibration was required for rerouting behavior.
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The object of the report is to reconsider the methods used to forecast kilometers per car at an average national level. Such forecasts are used as an input to the national traffic forecasts. The first part gives various sets of ti...
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The object of the report is to reconsider the methods used to forecast kilometers per car at an average national level. Such forecasts are used as an input to the national traffic forecasts. The first part gives various sets of time-series and cross-section data and draws certain conclusions about the effects of incomes, petrol prices and car speeds. A simple constant-elasticity model is then developed; it is used to illustrate the effects of a range of assumptions about the future. An alternative model of car ownership and use is then proposed. This has a disaggregate causal structure and uses ideas of utility maximization and constant travel budgets. The forecasts from both models cover a wide range; at the center of the range of the assumptions, they indicate little change in kilometers per car up to the year 2010. It is concluded that at its present stage of development the causal model is less satisfactory than the simple model. (Copyright (c) Crown Copyright 1981.)
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