The　objective　of　this　paper　is　to　study　the　operational　characteristics　of　exclusive　double　left-turn　lanes　at　signalized　intersections.　Data　for　exclusive　double　left-turn　lanes　were　collected　at　seven　signalized　intersections　with　protected　signal　phases　in　Beijing,　and　the　influence　of　lane　usage　and　u-turning　performance　on　double　left-turn　operations　were　analyzed.　Results　showed　that　the　proportion　of　lane　utilization　was　50　percent　in　both　of　lanes　for　a　double　left-turn　and　that　more　heavy　vehicles　tend　to　use　the　outside　lane.　The　observed　saturation　flows　yielded　a　mean　saturation　flow　of　1665　passenger　cars　per　hour　of　green　per　lane　(pcu/h/ln)　with　a　saturation　flow　interval　of　1587　-　1818　pcu/h/ln.　Also,　the　saturation　time　headway　between　the　inside　and　outside　left-turn　lanes　were　analyzed　using　independent　sample　T-tests.　It　was　concluded　that　there　was　no　significant　statistical　difference　between　the　outside　lane　and　the　inside　lane.　In　order　to　analyze　the　effect　of　u-turning　on　left-turn　saturation　flow　rates,　the　concept　of　u-turning　passenger　car　equivalent　(UTPCE)　was　introduced,　and　it　is　revealed　that　the　UTPCE　is　1.39.　Finally,　the　u-turning　adjustment　factor　for　the　left-turn　saturation　flow　rate　is　developed.　©　2010　ASCE.