NATCHEZ — If you drive across four bridges in Adams County, chances are one of them is considered insufficient by state and federal standards.

But don’t worry, most are not safety hazards, but they may be hazardous to the economy, one local legislator says.

Seventeen of the county’s 67 bridges receive less than a 50-percent grade given by the Office of State Aid Road Construction in Jackson and published through the National Bridge Inventory.

Those numbers are too high, says Rep. Robert Johnson, D-Natchez.

“A safe, solid bridge can be the difference between a driver having to take a detour around farm land to take materials or moving kids shorter distances back and forth from school,” Johnson said.

As chairman of the House Transportation Committee, Johnson said ensuring Mississippi’s roads and bridges are safe for motorists is key to moving the state forward.

A report from TRIP, a Washington, D.C.,-based national transportation organization, estimated 22 percent of Mississippi bridges are in need of repair, improvement or replacement. Fourteen percent of the state’s bridges are structurally deficient and eight percent are functionally obsolete.

Those figures and others were the catalyst for Johnson pushing for an increase to the state’s gasoline tax to pay for highway and bridge maintenance last year. Johnson’s bill died quickly after being introduced and to his frustrations with what he called a “culture of doing nothing.”

“We’ve tried to do everything we could politically to get funding increased, but nothing seems to be working,” Johnson said. “I just don’t think people understand how critical it is.”

Adams County Board of Supervisors President Darryl Grennell knows just how critical infrastructure is for the development of the area and has pushed for funding to repair several bridges in the county.

The following bridges are the five worst in Adams County according to ratings by the Office of State Aid Road Construction in Jackson:

-Lower Woodville Road over St. Catherine Creek — 17.8-percent rating.

-Sedgefield Road over Fairchilds Creek — 26.4-percent rating.

-Deerfield Road over Sandy Creek — 29.2-percent rating.

-Buckhurst Plantation Road over Walnut Creek — 30.3-percent rating.

-Upper Kingston Road over Second Creek — 31.2-percent rating.

Those ratings are based on a variety of factors including the bridge’s structural adequacy, safety and how essential it is for public use. Bridges on state highways, such as the Mississippi River Bridge at Natchez, are not included on the list.

The reports include the bridge’s sufficiency rating, year of construction and average daily traffic, among other things.

The rating formula used by the Jackson office calculates four factors to obtain a numeric value, which is indicative of the bridge’s sufficiency to remain in service.

The formula gives a percentage zero to 100, in which 100 percent represents an entirely sufficient bridge and zero percent represents an entirely insufficient or deficient bridge.

David Barrett, bridge engineer with the Office of State Aid Road Construction, said the sufficiency ratings are used to determine funding but also give an overall condition of the structure.

“You have to look at all of the things that go into that, but the sufficiency rating is a good indicator of where it’s at,” Barrett said. “In the federal funding formula, bridges less than 50 can be eligible for replacement so that’s kind of where they start looking for the ones that need the most attention.”

County engineer Jim Marlow, who also works with Jordan, Kaiser & Sessions engineering firm, said a low sufficiency rating doesn’t always mean the bridge is a danger to motorists.

“Even though you have some of those with low sufficiency ratings, that doesn’t mean the bridge isn’t structurally sound,” Marlow said. “Overall, Adams County is in pretty good shape.”

The report on the Lower Woodville Road bridge over St. Catherine Creek lists the bridge’s deck as being in poor condition and the substructure being in serious condition.

The report estimates 6,200 motorists travel the bridge daily, making it the second most traveled bridge in Adams County after the Canal Street bridge that goes over the railroad tracks. The Canal Street bridge sees an estimated 9,260 motorists daily. For comparison, 12,000 motorists travel each span of the Mississippi River Bridge at Natchez each day.

The Lower Woodville Road bridge, which was built in 1945, will soon be replaced.

Chris Dixon, district engineer with the Office of State Aid Road Construction, said the bridge needs to be repaired because of its antiquated design.

“I hate to say it’s an obsolete design because the bridge is working fine and has done so for many years, but it no longer meets the criteria forweight on bridges,” Dixon said. “Based on that criteria, the bridge is now deemed structurally deficient, but that doesn’t mean it’s about to fall in or anything.”

Dixon said new regulations have changed the capacity of weight the bridge can carry and must be rebuilt to handle industrial loads.

Earlier this month, the Adams County Board of Supervisors awarded a bid of $2,292,601.94 to Dozer Inc. to replace the bridge. The funds are part of Mississippi’s State Aid Road Program, which assists counties in the construction and maintenance of secondary, non-state owned roads and bridges.

Dixon estimates the bridge will be finished in fall 2015.

The bridge, Grennell said, is critical to handling industrial loads moving in and out of the Natchez-Adams County Port area.

“That bridge is an important industrial standpoint in Adams County because you have a lot of trucks that are carrying high tonnage that will be passing over that bridge going to and from the port,” Grennell said. “That’s why it was so important to make sure that bridge was replaced.”

The new bridge will be built adjacent to the current structure, which will be torn down after the new spans are completed.

Grennell said the Lower Woodville bridge is one of many the supervisors have identified and are in the process of fixing, stabilizing or replacing.

“We’re constantly trying to replace these old bridges or stabilize some of the existing bridges, but it’s a never-ending process,” Grennell said. “In theory, if we eventually get to every bridge in the county, you would have to recycle it and start back at the beginning of the list again by the time you were done.”

Securing funding for the projects is another issue Grennell said the county constantly faces.

“We’re always lobbying on the state and federal level to secure funding for those projects,” he said. “We’ve been talking to our legislative delegation to get more support of bridges in our area.”

The Mississippi Economic Council is planning a study looking for solutions to the state’s funding shortfall, but likely won’t make recommendations until after the 2015 state elections.

MEC officials estimated last month during a presentation of the study that Mississippi needs about $400 million more per year to maintain its current system.

A price tag for Adams County to replace all of its bridges could be in the range of $20 million, which is on the low end for some counties in the state, said Dixon, who overseas bridge projects in 10 other counties.

“To the general public 17 bridges seems high, but from an overall point of view it’s about average or less than other counties in the area,” Dixon said. “To replace those bridges would probably be between $15 to $20 million, and then the question is: where is that money going to come from?”