In　a　traffic　system　with　HOV　lanes,　considering　two　modes　of　driving　alone　and　carpooling,　we　proposed　three　kinds　of　travel　cost　functions　for　potential　commuters　such　as　carpoolers　in　HOV　lanes,　driving　alone　users　and　carpoolers　in　general　purpose　lanes.　Assume　that　all　commuters　will　experience　a　random　travel　time　with　discrete　distribution　during　their　trip,　this　paper　compared　the　commuters＇　equilibrium　choices　of　travel　mode　and　travel　route　under　the　framework　of　cumulative　prospect　theory　and　expected　utility　theory.　In　addition,　the　sensitivity　analysis　on　the　proportion　of　driving　alone　users,　the　individual　preference　such　as　the　reference　point　were　conducted.　The　resultant　observations　show　that　the　individuals＇　risk　preference　and　reference　dependence　definitely　affect　the　commuters＇　choices　on　the　travel　mode　and　travel　route.　When　the　proportion　of　driving　alone　users　exceeds　a　critical　value,　the　carpooling　users　will　be　better　than　driving　alone　users　since　they　have　higher　cumulative　prospect　value.　However,　this　critical　value　will　be　slightly　overestimated　under　the　framework　of　expected　utility　theory.　©　2016,　Editorial　Board　of　Journal　of　Systems　Engineering　Society　of　China.　All　right　reserved.