Adopted: April 21, 1994
WITH BRIDGE COLUMNS ON INTERSTATE 65
MAY 19, 1993
NTSB Number: HAR-94/02
NTIS Number: PB94-916202
On May 19, 1993, at 1:35 a.m., while traveling south on Interstate 65 near Evergreen, Alabama, a tractor with bulk-cement-tank semitrailer left the paved road, traveled along the embankment, overran a guardrail, and collided with a supporting bridge column of the County Road 22 overpass. Two spans of the overpass collapsed onto the semitrailer and the southbound lanes of the interstate, sending a cloud of cement dust into the air. An automobile and a tractor-semitrailer, also southbound, then collided with the collapsed bridge spans. The cement-tank truckdriver sustained serious injuries; the drivers of the other two vehicles were killed.
The National Transportation Safety Board determines that the probable cause of the accident was the truckdriver's failure to maintain his vehicle in the driving lane because of reduced alertness consistent with falling asleep. Contributing to the accident may have been the truckdriver's use of marijuana. Contributing to the severity of the accident was the collapse of the bridge, after the semitrailer collided with and demolished the north column, that was a combined result of the nonredundant bridge design, the close proximity of the column bent to the road, and the lack of protection for the column bent from high-speed heavy-vehicle collision.
The major safety issues discussed in this report are the truckdriver's possibly falling asleep, marijuana use, and the identification and evaluation of bridges that are vulnerable to high-speed heavy-vehicle collisions and subsequent collapse.
As a result of its investigation of this accident, the Safety Board makes recommendations to the Federal Highway Administration and the American Association of State Highway Transportation Officials.
As a result of its investigation. the National Transportation Safety Board makes the following recommendations:
to the Federal Highway Administration:
Request States to identify and assess bridges that are vulnerable to collapse from a high-speed heavy-vehicle collision with their bridge columns and develop and implement countermeasures to protectthe structures. (Class II, Priority Action) (H-94-5)
In cooperation with the American Association of State Highway Transportation Officials, ensure that the bridge management program guidelines include information on evaluating which bridges are vulnerable to high-speed heavy-vehicle collision and subsequent collapse. (Class II, Priority Action) (H-94-6)
to the American Association of State Highway Transportation Officials:
In cooperation with the Federal Highway
Administration, ensure that the bridge management program guidelines include
information on evaluating which bridges are vulnerable to high-speed
heavy-vehicle collision and subsequent collapse. (Class II, Priority Action)