A Review of the Evidence for the Temporal Transferability of Mode-Destination Models
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paper_title: A validation test of a disaggregate mode choice model

paper_content:

Abstract A model of work trip mode choice was developed on a sample of workers taken before Bay Area Rapid Transit (BART) opened for service. Validation tests of the model were performed on a sample of workers taken after BART service began. Two validation methods were used: (1) the actual mode shares in the post-BART sample were compared to the mode shares predicted by the models estimated on the pre-BART sample, and (2) the parameters of models estimated on the post-BART sample were compared with the parameters of the models estimated pre-BART. Three possible reasons were explored for the differences in actual and predicted shares and in the pre- and post-BART model parameters: (1) failure of the independence from irrelevant alternatives (IIA) property of the multinomial logit model, (2) non-genericity and incorrect data contributed substantially to the incorrect data for walk times. It was found that non-genericity and incorrect data contributed substantially to the mispredictions, while failure of the IIA property contributed less. The present study concerns only one model and one transportation environment. The results of this test, however, can be viewed along with the results of other validation studies to obtain a sense of the predictive ability of disaggregate mode choice models.
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paper_title: A COMPARISON OF THE PREDICTIVE ABILITY OF MODE CHOICE MODELS WITH VARIOUS LEVELS OF COMPLEXITY

paper_content:

Abstract Models of mode choice have recently been developed which include a large number of explanatory variables. The inclusion of some of these variables is obviously the result of trial-and-error analysis of various model specifications: the researcher tries various specifications until he obtains a specification which is consistent with a priori beliefs and fits the data fairly well. This method of model specification allows one to “learn” from the data, but is also open to the critism that the resultant model simply reflects relations which happen to exist in the sample, rather than true, behavioral relations. This paper examines this question. A complex model is presented which was developed after attempting a wide variety of specifications. The predictive ability of this model is compared with that of models with fewer variables, each of which could be included on the basis of a priori ideas. It is found that the complex model predicts best, indicating that the behavioral content of the model which was developed through “learning” from the data is greater than that of models which were specified on a priori beliefs.
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paper_title: SOME STUDIES OF THE TEMPORAL STABILITY OF PERSON TRIP GENERATION MODELS

paper_content:

Abstract In an attempt to assess the temporal stability of one type of person trip generation model (the category analysis model with the individual as the behavioural unit), some comparative studies based on the Reading Travel Surveys of 1962 and 1971 are described. Categories are defined with respect to a subset of the variables employment status, socio-economic group, household structure, car availability and household car ownership and particular attention is given to optional trips made by persons in certain employment status groups notably housewives and retired persons. Differences in trip rates between the two years are tested for statistical significance. In an introductory section the critical nature of assumptions concerning the stability of trip generation models which are to be used in situations where changes in mobility levels in the population are anticipated is emphasised. Following this the specification of the tested models is presented and the data sources are described, with particular attention to the synthesis of car availability data. It is tentatively concluded that the trip rates of certain groups in the population are susceptible to variation in response to changes in the level of accessibility.
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paper_title: TESTS OF THE TEMPORAL STABILITY OF TRAVEL SIMULATION MODELS IN SOUTHEASTERN WISCONSIN

paper_content:

The assumption of the stability of travel simulation models over time is as assential element of the urban transportation planning process. This assumption was tested using travel simulation models developed with data from an origin and destination survey conducted in 1963 and travel invensoty data from a similar study conducted in 1972. Both surveys were conducted by the Southeastern Wisconsin Regional Planning Commission; the travel models tested were those that had been used in the preparation of a regional land use and transportation plan for southeastern Wisconsin that was completed in 1966. The testing performed as a part of the reappraisal of the land use and transportation recommendations of 1966, which was of the temporal stability of the three major travel simulation models-trips generation, model split, and trip distribution-indicated that 1972 trip generation, transit use, and trip length characteristics within southeastern Wisconsin were predicted with adequate accuracy through the application of the original 1963 models. /Author/
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Title: A Review of the Evidence for the Temporal Transferability of Mode-Destination Models

Section 1: INTRODUCTION
Description 1: Discuss the importance of developing travel behaviour models that can replicate real-world travel choices and generate long-term forecasts. Introduce the concept of temporal transferability and highlight the need for evaluating it in the context of mode-destination models.

Section 2: Defining Transferability
Description 2: Define transferability with reference to existing literature and discuss its broad and narrow interpretations. Emphasize the focus on model transferability over underlying behavioural theories.

Section 3: Temporal and Spatial Transferability
Description 3: Differentiate between temporal and spatial transferability, outlining how each applies in the context of mode-destination choice models. Discuss the challenges and considerations involved in assessing these types of transferability.

Section 4: Conditions for Transferability
Description 4: Present the conditions under which models are considered transferable, citing prior research. Explore hypotheses and empirical tests from the early literature about disaggregate and aggregate models.

Section 5: Impacts of Violation of the Transferability Assumption
Description 5: Analyze the potential implications for forecasting when temporal transferability does not hold, emphasizing the added uncertainty to model predictions and the importance of understanding error sources.

Section 6: Assessing Transferability
Description 6: Discuss the methodologies used to test for temporal transferability, including statistical tests of parameter equality and predictive measures. Explain their significance and application in real-world model validation.

Section 7: LITERATURE REVIEW
Description 7: Review and synthesize key findings from the literature on temporal transferability of travel models, breaking studies down into sub-sections on mode choice, validation studies, and other relevant transferability research.

Section 8: Mode Choice Transferability Studies
Description 8: Detail studies that have investigated the direct temporal transferability of mode choice models, including both findings that support and challenge model parameter stability over time.

Section 9: Mode Choice Validation Studies
Description 9: Summarize research that has validated mode choice models by comparing predictions against observed mode shares, analyzing the significance of varying model specifications and their impact on transferability.

Section 10: Other Transferability Studies
Description 10: Present additional studies on the transferability of other model types, primarily focusing on trip generation models, and discuss their general findings about temporal stability and predictive accuracy.

Section 11: Summary and Critique
Description 11: Summarize the key findings from the literature on temporal transferability, noting gaps in research and limitations of existing studies. Critically assess the adequacy of current evidence in supporting long-term forecasting.

Section 12: DIRECTIONS FOR FUTURE RESEARCH
Description 12: Outline recommendations for future research aimed at improving the understanding of the temporal transferability of mode-destination models. Suggest methodologies and datasets that could provide new insights, and propose exploring the transferability of more advanced models.