In　this　paper,　we　proposed　to　use　a　driving　motion　capture　system　to　capture　and　interpret　driving　motion　for　a　better　understanding　of　driving　behavior,　which　is　crucial　to　highway　traffic　safety.　The　impetus　of　this　research　is　triggered　by　the　prevalent　success　of　a　motion　capture　system　in　other　disciplines,　such　as　computer　3D　animation,　bio-mechanics　and　athletic　sports　analysis.　Driving　motion　capturing　is　a　process　of　recording　and　tracking　drivers＇　body　movements,　obtaining　their　motion　parameters　in　a　three-dimensional　space.　The　established　driving　motion　database　created　through　this　capturing　system　can　be　used　to　analyze　the　impacts　of　human　fatigue　and　alcohol　on　driving　performance　under　varying　traffic　conditions.　©　2012　American　Society　of　Civil　Engineering.