Bad　weather　can　make　urban　traffic　congestion　worse.　Emergency　public　transit　can　be　applied　to　relieve　the　traffic　congestion　caused　by　bad　weather.　How　to　establish　an　emergency　public　transit　system　is　discussed.　The　system　mainly　contains　an　emergency　preplan,　a　network,　stations,　signals,　public　traffic　vehicles,　and　scheduling.　An　emergency　model　is　constructed.　An　evaluation　method　for　emergency　public　transit　is　put　forward.　Then　the　necessity　and　feasibility　of　applying　emergency　public　transit　system　is　analyzed　through　the　example　of　Beijing.　©　2011　ASCE.