Hazardous　locations　are　sites　with　higher　than　expected　frequency,　rate,　or　severity　of　crashes.　Identifying　hazardous　locations　is　used　in　deducing　underlying　causal　factors　and　implementing　potential　countermeasures.　A　summary　of　typical　methods　for　identifying　hazardous　locations　and　the　associated　problems　are　provided.　The　emphasis　is　placed　on　the　rate　quality　control　method.　A　brief　historical　perspective　on　the　development　of　the　rate　quality　control　method,　its　use　in　identifying　hazardous　locations,　and　its　strengths　and　weaknesses　are　presented.　The　limitation　of　collected　data　from　similar　locations　is　discussed.　An　improvement　is　provided　to　estimate　the　crash　rate　at　the　treated　site　where　it　is　difficult　to　get　locations　with　similar　characteristics　associated　with　the　rate　quality　control　method.　The　improvement　is　combining　the　rate　quality　control　method　with　the　Safety　Performance　Function　(SPF),　which　accounts　for　factors　which　probably　have　close　relationships　to　the　crash　rate　at　the　treated　site　and　the　reference　sites.　A　case　study　is　briefly　described　to　show　the　improvement.　©　2010　ASCE.