Plans to build an Interstate 49 extension through downtown Lafayette are lurching forward as planners wrap up about two years of revisions to a 2003 design. The revisions are not final decisions, and there remain open questions concerning Evangeline Thruway and the height of the elevated portion of the 5.5-mile roadway.

The team of consultants and state and federal officials devising the project — known as Lafayette Connector Partners — have presented the latest version of plans in a series of meetings this week with local officials and residents. The team has previously presented the revisions as individual pieces, but this is the first time the public has been able to view them in a single design.

One major change is replacement of interchanges at Johnston Street and 2nd and 3rd Streets with on-off ramps between Pinhook Road and University Avenue. A traditional diamond interchange has been added to the north at Willow Street. The idea is to reduce disruption to downtown traffic with access ramps along a frontage road, as opposed to interchanges directly at cross streets, Stephen Wallace, a principal with consulting firm Stantec, said while addressing a meeting of government officials on Wednesday.

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“We can change Evangeline in one way or another,” Wallace said, referring to the six-lane thruway currently running along the future interstate path, “but all the other streets stay connected and gridded.”

Evangeline Thruway at present is a six-lane “couplet,” with separate one-way roads with a mini block of real estate between them. The roads are in bad shape, and are considered dangerous to motorists and pedestrians alike.

The design team hopes to decide what to do with Evangeline in the next year. Lafayette officials want to replace it with a “grand boulevard” featuring abundant green space, pedestrian uses and several medians. The design team is choosing between the grand boulevard concept or leaving the basic structure in place. Despite the uncertainty, the city-parish is nevertheless applying for a $17 million federal grant to move forward with its concept.

Height is another uncertainty. As currently conceived, the interstate is elevated for 3.5 miles from roughly Willow Street to the Vermilion River. Planners are deciding whether to increase elevation from 22 feet to 30 feet along core downtown areas to allow for more light underneath the overpass.

Another major change is a shift in the path to avoid any damage to the historic Freetown-Port Rico neighborhood. To accomplish this, however, the Tobacco Plus and Exxon gas stations, as well as a barbecue restaurant connected to the Exxon station will be subject to eminent domain.

“It can range anywhere from having to take a little bit of their property, maybe part of their parking lot, to absolute full taking,” Michael McGaugh, a senior principal with Stantec, said in an interview, referring to the restaurant.

An employee at the restaurant, Lil Daddy’s Bar-b-q, said Wednesday the owner was unavailable for an interview.

The design team hosted an open-house informational meeting Thursday evening at Progressive Community Outreach Center, with graphics and maps blown up on cardboard displays. Milling among the crowd was Lionel Lyles, a consultant working with the McComb-Veazey Organization, a neighborhood development group. Lyles was focused on a display showing current and projected traffic volumes along Evangeline.

At present the daily traffic volume on Evangeline Thruway is 70,000 vehicles per day, according to the Lafayette Connector Partners’ display. That increases to 95,000 by 2040 without the new interstate. But with one, the volume would decrease to 26,000 with the interstate shouldering much of the traffic burden.

That presents a conundrum, Lyles said. Evangeline already cuts off the neighborhood, and more traffic on the ground would exacerbate the problem.

“This is a food desert and you don’t really have transportation. You’re kind of locked into the community,” Lyles said.

On the other hand, Lyles said, he is concerned a new interstate would create heavy noise pollution, and that construction would potentially unearth contaminated soil from the Union Pacific rail yard. That’s not to mention the possibility the interstate overpass could create havens for crime.

“It’s going to bring more people who are not necessarily local to the community, i.e. illicit activities,” he said.

Much about the project still needs to be figured out, said Monique Boulet, chief executive of the Acadiana Planning Commission. Boulet said the reduction in interchanges creates a “sleeker” design, and also results in a substantial, yet-to-be calculated cost reduction.

“We have taken hundreds of millions of dollars off the top of this thing,” Boulet said. “That’s where I think the community would really like to see (the state transportation department) invest and enhance it.”

Follow Ben Myers on Twitter, @blevimyers.