SORRENTO — With cars, trucks and 18-wheelers passing behind them, state and local officials on Monday marked the completion of a $5.6 million highway roundabout at a busy intersection in Ascension Parish that is a major route to the growing industrial corridor along the Mississippi River.

Already open for several weeks, the roundabout at La. 22 and La. 70 in Sorrento is one of several of the continuous flow, circular intersections planned in Ascension over the next several years and aimed at improving safety and breaking traffic bottlenecks.

Other state roundabouts are planned at the La. 30/Interstate 10 interchange and on La. 44 near Burnside, while parish government officials have a series of roundabouts planned on parish roads as part of the $70 million Move Ascension program.

Early last month, a home builder completed another $2.6 million roundabout on La. 44 just south of Gonzales as part of a joint city, parish and developer-financed project that also included new lanes on La. 44. The roundabout and lanes were connected to new home construction in the Conway and Oak Lake developments along La. 44.

The state's newly finished Sorrento roundabout is just south of the I-10 interchange. State highway officials say the new intersection, which is circular and allows continuous movement without dangerous left turns, will improve safety by ending backups on La. 70 and I-10 that occurred when workers were headed to plants in the morning and leaving them in the afternoon.

The new $9.4 billion Formosa Plastics chemical complex proposed in nearby northern St. James Parish and other industrial expansions in the area are expected to draw more traffic to the area.

During a news conference at the parish tourism office next to the new roundabout Monday, Gov. John Bel Edwards said that when top executives talk to him about locating new facilities along the river corridor, one of their biggest concerns is "connectivity to the interstate" for workers and delivery trucks.

"Because there's no better place than that river, but they need to be able to get their workers in and out and their goods and products in and out," he said. 

Edwards also emphasized that work on the roundabout, like other state projects, had continued through the outbreak of the novel coronavirus in the state and is part of $154 million in state road spending in Ascension Parish during his administration. That work includes the widening of La. 42 in Prairieville, which is expected to be finished at the end of 2020.

The state improvements in Sorrento also included sidewalks, new lanes along La. 22 between I-10 and La. 70, and a series of J-turns along La. 22 on either side of I-10, state officials said.

The J-turns, which promoted some concern from gas station owners along La. 22, are designed to improve flow through the entire area by limiting where drivers can make left turns that cross and interrupt traffic flow on La. 22.

Before the roundabout, the junction of the two two-lane highways had been controlled by stop signs and a blinking red light. The corridor, where more than 22,000 vehicles pass each day, was notorious for extended and unsafe backups, in particular, on I-10 eastbound in the early morning hours before sunrise.

Sen. Eddie Lambert, R-Prairieville, said he sat in those backups on I-10 and on La. 70, worrying about being rear-ended.

Saying "a lot of people had a lot of doubts" about how well the roundabout and other improvements would work, Lambert called the project a "home run" for DOTD.

"I know this thing is the best thing I've ever seen," Lambert said.

Shawn Wilson, secretary of the state Department of Transportation and Development, said the state has two other roundabout projects planned and fully funded in Ascension: three roundabouts and other corridor improvements at the I-10/La. 30 interchange in Gonzales and a roundabout along La. 44 just south of the Conway roundabout near Gonzales. 

The La. 30 roundabouts would help ease traffic in another busy corridor important to plant traffic farther down that highway but that also is a commercial hub for Gonzales, including the Tanger Outlets mall, Cabela's and The Home Depot near the I-10 interchange.

Wilson said state officials are working on resolving a "tremendous amount of utility conflicts" with the future interchange on La. 44 at Loosemore Road.

He said the La. 30 roundabouts are little more complicated because of I-10 and because of the volume and different mix of traffic in the area.

He said the state is also trying not to disrupt retail commerce when work would begin, but, at the same time, install the kind of corridor-length improvements that have been applied to the newly finished Sorrento project.

"You've got way more traffic on (La.) 30 than you do here, but this is an example of how the implementation would work," Wilson said. 

More than a decade ago, DOTD built Ascension Parish's first roundabout at La. 42 and La. 431 near Port Vincent, but, since around that same time, successive parish government administrations have also eyed roundabouts on parish roads in Ascension and haven't built one.

For years, engineers and consultants have told parish officials that eastern Ascension's grid-like road pattern lent itself well to roundabouts, but a lack of funding and a number of complications with acquiring land for the wide intersections and avoiding the industrial pipelines that crisscross the parish have for years kept those proposals off the drawing board.

The Move Ascension program may finally break that history, with nine roundabouts proposed in the current list of 35 projects.

The first two roundabouts, at La. 930 and Henry Road and at Parish Road 929 and La. 930, both in Prairieville, were heading early last month toward the construction phase, beginning with advertisement for bids from road builders, parish consultants have said.

Email David J. Mitchell at dmitchell@theadvocate.com

Follow David J. Mitchell on Twitter, @NewsieDave.