Respondent behavior in discrete choice modeling with a focus on the valuation of travel time savings.

For models of discrete choice and their parameter estimates we examine the impact of assuming that all attributes are deemed relevant to some degree in stated choice experiments, compared with a situation where some attributes are excluded (i.e., not attended to) by some individuals. Using information collected exogenous of the choice experiment on whether respondents either ignored or considered each attribute of the choice task, we conditioned the estimation of each parameter associated with each attribute and compare, in the context of tolled vs. free routes for noncommuting car trips, the valuation of travel time savings under the assumption that all attributes are considered and the alternative assumption of relevancy. We show empirically that accounting for the relevance of attributes will have a notable influence on the valuation of travel time savings. (Author/publisher)