[Updated 9:25 a.m. April 25 with new information from the Mobility Authority]

The Central Texas Regional Mobility Authority expects to start construction on the MoPac Improvement Project in the fall.

"We're certain there will be construction in the fall," Director of Communications Steve Pustelnyk said.

The MoPac Improvement Project will add one express toll lane in each direction on MoPac from Parmer Lane to Cesar Chavez Street. The Mobility Authority, which builds and operates toll roads in Central Texas, is overseeing the project.

Heather Reavey, vice president for HNTB—an architecture, construction, engineering and planning services firm contracted by the Mobility Authority—said that since the contract with CH2M Hill has been executed for the MoPac project, the design phase will begin. During the April 24 Mobility Authority board of directors meeting, she said CH2M Hill's proposal included some design modifications that will require CH2M Hill to review the environmental documents.

The design modifications include the connection from the toll lanes into downtown, she said. CH2M Hill is proposing to use underpasses and go under the existing main lanes instead of going over them. The company needs to have 30 percent of the design completed before construction can begin.

Pustelnyk said the first pieces of construction could involve utility relocation and building the sound walls. He said the Mobility Authority tentatively is looking at September for a ground breaking ceremony.

Members of the Mobility Authority's board of directors also expressed concern that the public might not know where the Mobility Authority is in terms of progress on the MoPac project. It has recently promoted Pustelnyk to director of community outreach for the project.

Reavey said part of the re-evaluation of the environmental documents also includes reaching out to affected stakeholders, and that outreach is likely to occur this summer.

Mobility Authority Executive Director Mike Heiligenstein said all proposals for the project, including the design modification that CH2M Hill is looking at for the connection into downtown, have already been reviewed.

"Our team was very sensitive to any proposals that would have violated the public trust that we have built during the public hearing process," he said.