An engineering study looking at the need to replace some of the 116 bridges in Bossier Parish has been completed and 12 of the parish’s larger structures have been prioritized for replacement over the next eight years.
Representatives from Forte & Tablada, the engineering firm that began the study in March of this year, reported findings during a Bossier Parish Police Jury road and subdivision committee meeting Wednesday.
Estimated cost to replace the bridges ranged from a high of just over $1.349 million to replace the Linton Road Bridge over Black Bayou reservoir, to $534,082 for a new structure over Flat River on the Atkins Clark Road.
Parish Engineer Butch Ford said the study focused on bridges more than six spans in length which parish crews would be unable to construct.
“We took into consideration a number of factors to determine which bridges we needed to seriously look at, including those we would be unable to do in-house,” Ford said. “We came up with the 12 bridges that our consultants studied.”
Forte & Tablada’s Joey Coco told police jury members the report focused on bridges that are of particular importance to Bossier Parish officials.
“We believe this prioritization study will provide Bossier Parish with a targeted approach for repairs and mitigation for the chosen bridges, and will allow for a scientific approach to best utilize public funds,” Coco said.
Coco said the study considered a broad range of variables including load carrying capacity (of the bridge), average daily traffic, significant routes served, dead-end potential, the number of rooftops within a two-mile radius, the number of (oil and gas) well sites within a four-mile radius and the length of alternate routes.
Most of the bridges in the study shared a common characteristic, Coco pointed out.
“The 12 bridges identified were quite similar in their composition, with 11 of the 12 comprised completely of timber substructure and superstructure components and only one bridge having a concrete superstructure with a timber substructure,” he said.
Cost estimates on the bridges were compiled using recent Louisiana DOTD bid tabulations for comparable bridges, Coco said.
Remaining bridges in the study and cost estimates, by priority, include Smith Rd. over Flat River, $691,817; Elston Rd. over Red Chute Bayou, $1,109,533; Sligo Rd. over Foxskin Bayou, $770,685; Caplis Sligo Rd. over Red Chute Bayou, $933,208; Swan Lake Rd. over Flat River, $799,285; Johnson Koran Rd. over Foxskin Bayou, $612,950; Smith Rd. over Red Chute Bayou, $1,021,371; Ivan Lake Rd. over Ivan Lake reservoir, $1,165,024; Swan Lake Rd. over Red Chute Bayou, $1,374,021; Log Ferry Rd. over Posten Bayou, $691,871.
Road committee chairman Glenn Benton said police jury members and staff would review the report’s findings and recommendations and determine how to proceed.