This　paper　validates　the　vehicle　type-dependent　car-following　heterogeneity　from　micro-　and　macro-aspects　by　using　Next　Generation　Simulation　(NGSIM)　trajectory　data.　Regarding　the　micro-viewpoint,　traffic　conflict　analysis　techniques　and　three　surrogate　safety　indexes　(i.e.,　time　headway　(TH),　time　to　collision　(TTC)　and　safety　margin　(SM))　are　introduced　to　evaluate　the　safety　performance　during　＇steady＇　car　following.　When　driving　or　following　a　larger　vehicle,　Z-test　results　show　that　TH,　TTC　and　SM　all　become　higher　significantly,　that　is,　the　driver＇s　accepted　risk　tends　to　be　lower.　From　the　macro-viewpoint,　with　the　aggregated　traffic　data,　a　flexible　Lagrangian　fundamental　diagram　is　calibrated　by　a　bi-level　optimization　procedure.　These　calibrated　curves　illustrate　that　during　close　car　following　process　with　the　same　speed,　the　driver　generally　keeps　a　higher　gap　distance　with　the　leader　when　following　or　driving　a　larger　vehicle.　Therefore,　the　consistent　findings　contribute　to　the　conclusive　results　about　the　vehicle　type-dependent　car-following　heterogeneity.