By　analyzing　the　safety　interactive　relation　between　vehicle　and　road　surface　use,　it　can　be　concluded　that　antislippery　performance　of　road　surface　is　a　key　factor　for　appraising　safety　of　road　surface　use　and　six　basic　coefficient　indexes　have　been　put　forward:　Transit　allow　friction,　Side　allow　friction,　Transit　require　friction,　Side　require　friction,　Transit　and　Side　safety　state　＇standard　value＇,　a　set　safety　model　of　road　surface　use　is　set　up.　By　testing　and　comparing　with　traffic　accident　type　of　a　case　in　a　section　of　class　II　of　NH　(national　highway),　the　road　safety　model　of　surface　use　is　feasible　and　its　coefficient　of　friction　Quantized　standard　Δf　=　13.2　which　has　been　attained.　It＇s　higher　than　the　minimum　value　of　bituminous　penetration　macadam　or　gravel　in　highway　maintenance　specification.　It　is　easy　to　lead　traffic　slip　accident.