This schematic map from the state highway department shows the planned layout for a detour bridge around the southbound Airline Highway span at Bayou Manchac on the East Baton Rouge-Ascension Parish line. The detour bridge is in the upper portion of the map. Contractors working for the state Department of Transportation and Development are preparing to replace the southbound Airline bridge. Traffic will use the detour bridge while the replacement work occurs, DOTD officials said.

PRAIRIEVILLE — One lane on the southbound Airline Highway span over Bayou Manchac will be closed for more than two weeks starting Tuesday to prepare for replacement of the bridge, state highway officials said.

The state is spending nearly $10 million to replace both Airline bridges over Manchac: the Ascension-East Baton Rouge Parish line and the southbound bridge over Bayou Francois in Gonzales to the southeast.

Contractors working for state State Department of Transportation and Development are also planning to do road paving work around the new bridges, DOTD plans show.

All three bridges being replaced on Airline, which is also known as U.S. 61, were built in the early 1950s and have reached their designed life expectancy, state highway officials have said.

The Manchac bridges are near the State Fairgrounds, which is BREC's Airline Highway Park, in Baton Rouge.

Contractors will close the right southbound lane of Airline on Tuesday while they tie in a detour route to go around that bridge for the replacement work, highway officials said in a statement.

The lane closure is expected to last until Dec. 20.

Once finished, the southbound bridge at Airline will be closed and traffic on Airline will use the detour instead until a new southbound bridge is built.

The work on the new concrete span is expected to finished by the summer. 

No vehicles wider than 12 feet will be allowed to pass through the lane closure area until Dec. 20, DOTD officials said.

Work began on the bridge replacement project in September. Last month, contractors instituted land closures and did other related work for a similar detour bridge at Bayou Francois in Gonzales. 

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