The　expressways　which　were　built　at　the　end　of　the　1980＇s　and　the　beginning　of　1990＇s　exist　some　design　deficiency　due　to　the　absence　of　national　technical　standard　at　that　time,　and　this　leads　to　safety　hidden　trouble.　At　the　same　time,　almost　all　the　expressways　exist　problems　like　volume　over　load,　too　many　crash　accidents.　So,　broadening　is　a　good　chance　to　improve.　The　paper　analyzes　the　design　factors　which　influence　the　traffic　safety　and　evaluates　the　current　Chinese　design　specification　on　median,　shoulder,　roadside,　curb　and　the　ramp＇s　length　of　the　interchange.　Some　suggestions　which　may　be　useful　to　improve　the　road　safety　are　also　put　forward.