This　paper　mainly　focuses　on　the　configuration　location　designation　of　variable　message　sign.　The　random　error　term　of　Probit　traffic　assignment　model　stands　for　the　difference　between　roadway　situation　and　traveler＇s　expectation　and　it　has　an　effect　on　the　assignment　result.　Different　assignments　result　in　different　roadway　network　situations.　In　this　paper,　the　BPR　function　and　HCM2000　signalized　intersection　delay　model　are　taken　to　evaluate　the　roadway　network　operations　and　variable　message　sign　locating　procedure　is　also　set　up.　A4×4　roadway　network　is　taken　as　the　numeral　sample　and　the　best　location　of　variable　message　signs　are　determined.　Based　on　the　method　mentioned　above,　the　influence　of　information　coverage　on　the　roadway　network　operations　and　the　influence　of　information　accuracy　on　the　roadway　network　operations　are　discussed.　The　results　show　that　the　total　expected　roadway　network　travel　time　tends　to　decrease　with　the　expansion　of　information　coverage　and　improve　of　the　information　accuracy.