Standing under a big canopy covering part of the Sunshine Bridge, it almost felt like being inside a tent, except a really cavernous one with really thick, gray tent poles.

One also could almost forget the spot was roughly 180 feet in the air while cars, trucks and tractor-trailers sped just below and, well below that, the Mississippi River flowed by.

Only a look over the edge at the river or the occasional rush of an 18-wheeler, which caused the corrugated flooring on which people stood above the bridge deck to roll with a slight wave, offered a reminder of where this really was.

The containment canopy is covering the scene of a $25.1 million state highway project to blast off rust, refurbish and repaint the superstructure of the Sunshine Bridge’s main span. State highway officials overseeing the project gave a tour Friday morning as they announced the project is about 55 percent complete after more than 14 months of work.

Rodney Mallett, spokesman for the state Department of Transportation and Development, said workers with North Star Painting Co. are still blasting, painting and repairing sections of the bridge.

“And we hope to have all four lanes back open in early 2016,” he said.

The project has limited the bridge to two lanes since mid-March 2014 as nearby CF Industries in Donaldsonville began undergoing a $2.1 billion expansion that drew hundreds of construction workers.

State Sen. Troy Brown, D-Geismar, and state Rep. Ed Price, who were on the tour, both said their constituents continue to be concerned about the traffic delays and length of the bridge project.

“Everybody wants to know when are we going to be relieved of this traffic congestion,” Price, D-Gonzales, told state highway project engineer Michael Ricca in a meeting before the tour.

Some drivers and officials initially questioned the timing of the bridge project, coinciding with the CF Industries expansion, which is projected to end in 2016, as well.

But DOTD officials have said the repairs could not wait and would risk more expensive repairs later if the agency had waited and corrosion had worsened.

Chad Vosburg, DOTD district administrator for the Baton Rouge area, reiterated that point Friday. He said the bridge had gotten to a point that DOTD had to take action to avoid having to post weight limits in the future.

DOTD officials did not immediately have the bridge’s inspection rating before the paint job began, but last fall, U.S. Department of Transportation officials said Louisiana’s 2013 list of bridge ratings described the Sunshine Bridge as “structurally deficient.”

That means the bridge is safe but needs repair, closer monitoring or weight restrictions to prevent it from becoming unsafe.

Workers have been blasting the rust and paint off the cantilever bridge’s metal truss spans and replacing old rivets with bolts and attending to other rusted-out parts. The bridge, which was opened in 1964, was last repainted in 1980.

The workers are sealing and caulking joints and other spots known to corrode and are applying three layers of paint, including the familiar top coat called Louisiana gray.

Friday’s tour went through two phases of the job, a largely completed section and one still being painted, which is one of the areas under the canopy. The tour did not go to another canopied area where paint and rust were being blasted off.

Ricca and George Pilatos, North Star quality control supervisor, showed Brown, Price and Ascension Parish Chief Administrative Officer Ken Dawson how the different coats of paint have different colors to ensure total coverage. Ricca added the paint thickness is still checked later to ensure it meets standards.

“There’s a requirement not only for each coat but for the total amount of coverage,” Ricca told Dawson.

Ricca said the painting part of the job is about 65 percent to 70 percent complete. Other repairs and refurbishing that had been anticipated before the painting project began are being done as the bridge is being repainted, Ricca said.

But he said the need for additional repairs came to light after the project started and will require continued lane closures after painting is mostly finished in mid-September. Those repairs have not been designed yet.

“The issues came up during the course of the work, and, actually, if we had the answer right now, we could be working on it, but until we get that answer, we can’t start,” Ricca said.

“And I don’t expect that we’ll get the information needed to do that work until we’re pretty much done (with the painting).”

He added that to finish the paint job completely, workers have to reconfigure the lane restrictions this fall so that traffic moves in the outside lanes along each side of bridge. The two open lanes are currently on the upriver side of bridge, so drivers face oncoming traffic divided by concrete barriers.

Follow David J. Mitchell on Twitter, @NewsieDave.