Judgments in the selection of path generation techniques: a meta-analytic approach

In the context of modeling route choice behavior, modelers generate objective choice sets by selecting a path generation technique and its parameters according to personal judgments. The current paper proposes an experimental setting and a methodological approach to provide indications about objective judgments for effective route choice set generation. Initially, path generation techniques are implemented within a synthetic network to generate possible subjective choice sets considered by travelers. Next, “true model estimates” and “postulated predicted routes” are assumed from the simulation of a route choice model. Then, objective choice sets are applied for model estimation and results are compared to the “true model estimates”. Last, predictions from the simulation of models estimated with objective choice sets are compared to the “postulated predicted routes”. Meta-analysis allows synthesizing the effect of judgments on the implementation of path generation techniques, since a large number of models generate a large amount of results that are otherwise difficult to summarize and to process. Meta-analysis estimates suggest that modelers should apply stochastic approaches with the possibility of correcting for unequal sampling probability while maintaining a fairly reasonable level of variance. Estimation of models would greatly improve and the issue of the coverage of observed behavior would not be raised because the correction would cover for adding alternatives not generated.