This　paper　demonstrates　the　existence　and　variety　levels　of　loss　aversion　in　travel　behavior　using　a　stated-preference　survey　and　psychology　experiment　(sample　size　76).　Loss　aversion　is　one　of　the　key　points　that　differentiate　prospect　utility　from　expected　utility.　Using　a　psychology　experiment　based　on　elicitation　methods,　this　paper　identifies　loss　aversion　parameter　in　route　choice　behavior　of　each　traveler.　The　results　indicate　that　60%　percent　of　respondents　show　loss　aversion　with　a　median　value　of　1.27.　So　loss　aversion　can　be　found　in　traveler’s　route　choice　behavior　and　heterogeneity　is　significant.　The　statistic　result　shows　that　the　risk　preference　of　commuters　in　loss　domain　is　different　from　that　in　gain　domain,　as　well　the　attributes　of　traveler　contributing　to　risk　preference　are　quite　different.　Linear　discriminant　analysis　indicates　that　in　gain　domain　travelers　are　more　likely　to　be　risk　aversion　and　personal　socioeconomic　characteristics　contributing　this.　On　the　other　hand,　in　the　loss　domain　travelers　are　more　likely　to　be　risk　seeking　and　traffic　conditions　relate　to　this.　By　looking　into　proportions　of　travelers　choosing　Route　A　and　B,　risk　preference　reversal　under　different　loss　aversion　levels　is　found.　©　2016,　UK　Simulation　Society.　All　Rights　Reserved.