We propose a framework to find optimal price-based policies to regulate markets characterized by oligopolistic competition and in which consumers make a discrete choice among a finite set of alternatives. The framework accommodates general discrete choice models available in the literature in order to capture heterogeneous consumer behavior. In our work, consumers are utility maximizers and are modeled according to random utility theory. Suppliers are modeled as profit maximizers, according to the traditional microeconomic treatment. Market competition is modeled as a non-cooperative game, for which an approximate equilibrium solution is sought. Finally, the regulator can affect the behavior of all other agents by giving subsidies or imposing taxes to consumers. In transport markets, economic instruments might target specific alternatives, to reduce externalities such as congestion or emissions, or specific segments of the population, to achieve social welfare objectives. In public policy, different agents have different individual or social objectives, possibly conflicting, which must be taken into account within a social welfare function. We present a mixed integer optimization model to find optimal policies subject to supplier profit maximization and consumer utility maximization constraints. Then, we propose a model-based heuristic approach based on the fixed-point iteration algorithm that finds an approximate equilibrium solution for the market. Numerical experiments on an intercity travel case study show how the regulator can optimize its decisions under different scenarios.
This paper presents a new approach to the fuzzy estimation of the variables of complex, fast, closed-loop systems. It is used to develop an original real-time longitudinal velocity estimator for FWD cars. Its application covers highly critical driving situations and avoids the use of an expensive optical cross-correlation sensor. The aim is to provide vehicle monitoring processes with a reliable value of the longitudinal velocity. Fuzzy aggregate indicators are used to identify and detect the different ways a vehicle behaves. Then, a fuzzy expert system with rules based on these indicators decides which values should be used among those which allow the estimation of the longitudinal velocity. 相似文献
We investigate how customers respond to an opaque airline product offered by a European carrier. In this opaque product design, customers are randomly assigned to travel to one of approximately ten destinations; however, for a fee they may exclude one or more destinations from the choice set (or a particular package design) prior to learning which destination they will travel to. We use a multidimensional binary logit model to predict the probability that one or more alternatives will be chosen by a customer. Results show that customers are more likely to pay to exclude destinations located close to the origin airport and destinations that speak the same language as the origin airport. Length of stay, cost of living at the destination, and measures of destination attractiveness are also found to be significant predictors for some package designs. Based on these findings, we offer general recommendations for how to design opaque packages for airline customers. 相似文献
This is a practical implementation of a multicriteria methodology developed to assess the risk involved in investment or policy projects. It is based on the specification of a non-linear, but piecewise linear, additive utility function, where the partial utility functions are specified as recursive exponential functions of only one curvature parameter. This allows for a reduction of the quantity of information necessary to build the utility function in a context of uncertainty. It is introduced in an aggregation model whereby the partial utility functions are built separately through a specific questioning process. The methodology is applied to the selection of road infrastructure projects of the Walloon Region in Belgium with several experts and civil servants from the Transport Ministry whose individual utility functions are derived. Software called MUSTARD is used, which stepwise and interactively helps the decision-makers to formulate the problem, build the criteria's distributions and state their preferences. The projects are ranked according to their rate of return computed on the basis of the projects' certain equivalent money values. 相似文献
This paper attempts to measure the impacts of urban transportation system improvements or changes on the community. The community's perceptions of the impacts are represented by its utilities (or disutilities) over various ranges of values of the multiple attributes representing these impacts. The utility technique used in the evaluation is based upon von Neumann‐Morgenstern (vN‐M, 1947) Utility Theory, and is applied using Raiffa's (1970) Fractile Method. The paper specifically applies the technique to model the perceptions of five subgroups within a community to the impact of a new light rail transit system that is being incorporated in the transportation system of the City of Calgary. Results of the modeling indicate explicitly how the community changes its perception over ranges of values of the attributes evaluated. Biases of various subgroups within the community over these attributes are also shown. Statistical tests indicate that aggregated utility perceptions can represent the utility perceptions of the individual subgroups quite reasonably. 相似文献
Those designing surveys and producing data have always been concerned about its quality. The increasing stringency of the financial constraints which affect public authorities and the increased scope of involvement in the regulation of urban travel has led us to pay even greater attention to the quality of data. This issue is frequently covered in the literature on survey methods. However, comparisons between different survey methods are more rarely conducted. The decision to conduct such an analysis is partly the result of the development of telephone use to the detriment of other survey modes in many countries and also the development of Computer-Aided Telephone Interviewing (CATI) which facilitates the running and monitoring of the survey.This paper examines several aspects of this question in order to compare the performance of telephone and face-to-face interviews. The first aspect is the representativeness of the sample, and therefore relates mainly to the issue of nonresponses and the choice of a sample base. The second concerns the accuracy of the information and involves the choice of a survey area and the recording of all trips, including short-distance travel. Finally, the quality of data is obviously determined by the quality of the responses given by those interviewed.The answers we give frequently depend on the objective of the surveys, which leads us to put forward a table which summarizes the performance of telephone and face-to-face interviews on the basis of the main objective of the survey. Broadly, the telephone seems to be the favoured tool for surveys in the area of transport planning and surveys which aim to provide data for forecasting models, mostly on the grounds of cost. However, face-to-face techniques are often preferred for surveys which aim to discover and analyze the factors which explain individual travel behaviour. 相似文献
The primary purpose of this study was to investigate how relative associations between travel time, costs, and land use patterns
where people live and work impact modal choice and trip chaining patterns in the Central Puget Sound (Seattle) region. By
using a tour-based modeling framework and highly detailed land use and travel data, this study attempts to add detail on the
specific land use changes necessary to address different types of travel, and to develop a comparative framework by which
the relative impact of travel time and urban form changes can be assessed. A discrete choice modeling framework adjusted for
demographic factors and assessed the relative effect of travel time, costs, and urban form on mode choice and trip chaining
characteristics for the three tour types. The tour based modeling approach increased the ability to understand the relative
contribution of urban form, time, and costs in explaining mode choice and tour complexity for home and work related travel.
Urban form at residential and employment locations, and travel time and cost were significant predictors of travel choice.
Travel time was the strongest predictor of mode choice while urban form the strongest predictor of the number of stops within
a tour. Results show that reductions in highway travel time are associated with less transit use and walking. Land use patterns
where respondents work predicted mode choice for mid day and journey to work travel.
T. Keith LawtonEmail:
Lawrence Frank
is an Associate Professor and Bombardier Chair in Sustainable Transportation at the University of British Columbia and a
Senior Non-Resident Fellow of the Brookings Institution and Principal of Lawrence Frank and Company. He has a PhD in Urban
Design and Planning from the University of Washington.
Mark Bradley
is Principal, Mark Bradley Research & Consulting, Santa Barbara California. He has a Master of Science in Systems Simulation
and Policy Design from the Dartmouth School of Engineering and designs forecasting and simulation models for assessment of
market-based policies and strategies.
Sarah Kavage
is a Senior Transportation Planner and Special Projects Manager at Lawrence Frank and Company. She has a Masters in Urban
Design and Planning from the University of Washington and is a writer and an artist based in Seattle.
James Chapman
is a Principal Transportation Planner and Analyst at Lawrence Frank and Company in Atlanta Georgia. He has a Masters in Engineering
from the Georgia Institute of Technology.
T. Keith Lawton
transport modeling consultant and past Director of Technical services, Metro Planning Department, Portland, OR, has been active
in model development for over 40 years. He has a BSc. in Civil Engineering from the University of Natal (South Africa), and
an M.S. in Civil and Environmental Engineering from Duke University. He is a member and past Chair of the TRB Committee on
Passenger Travel Demand Forecasting. 相似文献
An end-user query of a Geographical Information System (GIS) can formally be defined as the application of a set of operators (spatial or not). Geographical Information Systems used for Transportation (GIS-T) must provide a path evaluation operator. For example, an end-user query may involve a selection based on alphanumeric criteria, an evaluation of path, and a spatial intersection. This composition of operators and the fact that the evaluation of a path may not provide a unique result impose the definition of a query resolution model or a database query language able to support this composition. In this paper we present a query resolution model. The use of multi-criteria analysis and the definition of aggregates in a query (nearly mandatory) may involve ambiguities in the final presentation of the results to an end-user. The formal modeling of query results must take into account this risk. The philosophies of a query definition and the presentation of the results may be different (e.g., formular vs visual). The management of query results must take into account the data model associated with the query results, the results themselves (metabase/database), and the interpretation. The interpretation avoids errors due to visual ambiguities of an operator with an aggregate function. 相似文献