Posted 5-15-08

Damage to WYO 450 Bridge Can't Be Repaired

(WYDOT) -- The deck and girders of the WYO 450 bridge struck by a coal truck Tuesday are too severely damaged to be repaired and will have to be replaced.

As a result, the highway section about 10 miles east of Wright will remain closed and the current detour around the damaged bridge using gravel county roads between Highlight Road and School Creek Road is expected to continue at least through the end of this week. Digital message signs and arrow boards are directing traffic to and thru the detour.

WYDOT is working with Thunder Basin Coal Co. to determine the best plan for restoring traffic to WYO 450 and the coal mine haul road that crosses underneath. A Thunder Basin truck hauling coal under the bridge Tuesday tore out one of the four support girders and severely damaged a second, causing the bridge above to sag two to three feet.

WYDOT Assistant State Bridge Engineer Keith Fulton said the abutments on each side of the bridge look to be in good condition, so one option being considered is building a temporary bridge on those structures.

Other alternatives are building the temporary bridge beside the damaged bridge or building a short detour around the damaged bridge intersecting the coal mine haul road. That option would require 24-hour traffic control because of the volume of coal truck traffic using the road. WYO  450 carries an average of about 1,830 vehicles a day, including about 300 trucks.

"We're looking for the best and safest option to get the road reopened as soon as possible," Fulton said.