National Transportation Safety Boardwashington,d.c.20594 Safety Recommendation

摘要

The National Transportation Safety Board is an independent Federal agency charged by Congress with investigating transportation accidents,determining their probable cause,and making recommendations to prevent similar accidents from occurring.We are providing the following information to urge your organization to take action on the safety recommendations in this letter.The Safety Board is vitally interested in these recommendations because they are designed to prevent accidents and save lives. These safety recommendations address insufficient bridge design firm quality control procedures,lack of guidance for bridge owners with regard to the placement of construction loads on bridges during repair or maintenance activities,exclusion of gusset plates in bridge load rating guidance,lack of inspection guidance for conditions of gusset plate distortion,and inadequate use of technologies for accurately assessing the condition of gusset plates on deck truss bridges.The recommendations are derived from the Safety Board's investigation of the collapse of the I-35W highway bridge in Minneapolis,Minnesota,on August 1,2007,and are consistent with the evidence we found and the analysis we performed.As a result of this investigation,the Safety Board has issued nine safety recommendations,six of which are addressed to the American Association of State Highway and Transportation Officials (AASHTO).Information supporting the recommendations is discussed below.The Safety Board would appreciate a response from you within 90 days addressing the actions you have taken or intend to take to implement our recommendations.