We herein use the results of laboratory experiments to study the effects of preference-elicitation mechanisms on the efficiency of auctions. Transportation and reservation service providers need to know the potential user demand. However, the preference-elicitation method can impact the elicitation results. In this study, we experimentally analyze the effects of preference-elicitation mechanisms on users’ eliciting behaviors and on the efficiency of auction results. In addition, we show that our preference-elicitation mechanism can reduce users’ bidding cost and improve the efficiency of auction results. Finally, we examine users’ behaviors in laboratory experiments to estimate their preference-elicitation costs.