The　traffic　safety　is　closely-related　with　the　physiological　and　mental　characteristics　of　the　drivers.　Drivers　with　different　temperament　will　incline　to　drive　the　vehicle　in　different　ways,　which　will　bring　about　different　influence　on　the　traffic　safety.　It　is　concluded　by　the　analyses　of　the　average　travel　speed　according　to　different　drivers　that:　drivers　with　choleric　temperament　are　full　of　adventure　and　drive　the　most　quickly　with　the　high　latent　occurrence　of　traffic　accident;　while　the　melancholic　ones　drive　lower　and　more　carefully.　This　paper　provides　a　useful　method　to　the　further　study　on　the　relationship　between　the　physiological　and　mental　characteristics　of　the　drivers,　especially　the　drivers＇　temperament,　and　the　traffic　safety.