This publication contains detailed guidelines for the planning, conduct, and use of safety engineering studies at identified hazardous locations. The publication should be beneficial to highway engineers and other professionals involved in highway safety and/or traffic operations. The objectives of this publication are to: (1) plan an effective highway safety engineering investigation of an identified hazardous location; (2) perform a highway safety engineering investigation of an identified hazardous location, using appropriate procedures and techniques; (3) select the most appropriate procedures and techniques required for safety engineering studies, considering agency size and type; (4) identify safety deficiencies and feasible countermeasures that are necessary to alleviate the hazardous situation; and (5) select a safety project based on safety objectives.