Golden, Colorado
May 15, 2004
NTSB Number: HAB-06-01
Adopted May 31, 2006
PDF
On May 15, 2004, about 10:04 a.m., mountain daylight time, a 2002 Dodge Durango sport utility vehicle (SUV) driven by a 34-year-old man eastbound on Interstate 70 (I-70) approached the Colorado State Route 470 (C-470) overpass. The driver's 37-year-old wife and their 2-year-old child were also in the SUV. The interchange of I-70 and C-470 was in a temporary traffic control zone for a highway construction project, during which an additional entry ramp and two additional lanes were being constructed for the overpass.
As the SUV approached the overpass, a fabricated steel girder line composed of two joined sections, which had been erected during the evening of May 11 through the early morning hours of May 12, 2004, parallel to the existing overpass, as a part of the bridge-widening project, rotated toward the overpass and sagged into the I-70 eastbound lanes. The girder struck the SUV about half the distance between the vehicle's front end and its windshield and sheared off the vehicle's top. The lower portion of the SUV continued east for 818 feet, coming to rest in the grassy median of I-70. All three vehicle occupants were killed.
The Safety Board determines that the probable cause of the May 15, 2004, girder collapse in Golden, Colorado, during a highway bridge-widening project was the failure of the girder's temporary bracing system due to insufficient planning by Ridge Erection Company, Inc., Asphalt Specialties, Inc., and the Colorado Department of Transportation, which were responsible for putting the girder and its bracing in place, and due to deficiencies in the installation of the girder and the bracing, so that the bracing ultimately failed to adequately secure the out-of-plumb girder to the existing bridge deck. Contributing to the accident were the lack of uniform, consistent bracing standards and the Colorado Department of Transportation's narrow definition of falsework, which did not include lateral bracing. Also contributing to the accident was the failure of the Colorado Department of Transportation to effectively oversee safety-critical contract work for the project.
As a result of this accident investigation, the National Transportation Safety Board makes the following safety recommendations:
To the Federal Highway Administration:
Take the lead in working with the Occupational Safety and Health Administration and the American Association of State Highway and Transportation Officials to make consistent and compatible your organizations' regulatory requirements for and guidance to construction contractors concerning the design and certification of falsework, formwork, and bracing for the erection of highway structures, including the regulations and guidance concerning the need to have the designs prepared or approved by a Registered Professional Engineer. (H-06-22)
To the Occupational Safety and Health Administration:
Work with the Federal Highway Administration and the American Association of State Highway and Transportation Officials to make consistent and compatible your organizations' regulatory requirements for and guidance to construction contractors concerning the design and certification of falsework, formwork, and bracing for the erection of highway structures, including the regulations and guidance concerning the need to have the designs prepared or approved by a Registered Professional Engineer. (H-06-23)
To the Colorado Department of Transportation:
Require your State highway and transportation department supervisory construction personnel to actively supervise and monitor safety-critical work being accomplished by contract workers. At a minimum, State supervisory personnel should 1) prequalify all subcontractors performing safety-critical work on highway projects and 2) intervene when a contractor or subcontractor exhibits a lack of competence. (H-06-24)
To the American Association of State Highway and Transportation Officials:
Work with the Federal Highway Administration and the Occupational Safety and Health Administration to make consistent and compatible your organizations' regulatory requirements for and guidance to supervisory construction contractors concerning the design and certification of falsework, formwork, and bracing for the erection of highway structures, including the regulations and guidance concerning the need to have the designs prepared or approved by a Registered Professional Engineer. (H-06-25)
Revise the guidance in your Construction Manual for Highway Construction that pertains to the role of State highway and transportation departments' supervisory construction personnel to ensure active supervision and monitoring of safety-critical work being accomplished by contract workers. At a minimum, the guidance should call for State supervisory personnel to 1) prequalify all subcontractors performing safety-critical work on highway projects; 2) require the contractor or subcontractor to submit a written plan or design drawings for all construction, including temporary falsework and bracing, and to have these plans or drawings reviewed and approved by a Registered Professional Engineer; 3) intervene when the contractor or subcontractor exhibits a lack of competence; and 4) require the contractor or subcontractor to take reasonable precautions to monitor and ensure the continued stability of temporary bracing or falsework until permanent construction is completed. (H-06-26)
