The Central Texas Regional Mobility Authority will likely seek the same design/build process used on the MoPac and 183 South toll projects for the new 183 North toll project in Northwest Austin.

The proposed 183 North project would add two new toll lanes in each direction on US 183 from MoPac to RM 620, connecting to the Toll 183A lanes in Cedar Park. Direct connectors would also be built to the MoPac express lanes and eventually to RM 620 when needed. The total cost is estimated at $650 million, of which $150 million would fund the RM 620 direct connectors.

Mobility Authority staffers are recommending a design/build process, which involves overlapping the design and construction phases to expedite a project, said Justin Word, the agency’s director of engineering. Another method of building roads is the design/bid/build process that requires completing the design first before beginning construction.

“The fact is both models are viable,” Word said. “Either one could deliver the project … but there’s a few key [points] that tilt staff toward design/build.”

Advantages to the design/build process include lower upfront costs, entering the bond market sooner for financing and beginning construction sooner.

In a design/bid/build process, Word said the agency would have full control of the design and fully fleshed out plans and defined project scope. However, the process does take longer.

“The takeaway is we’re looking at a roughly nine-month advantage for design/build,” Word said.

Word said the construction market is more favorable for a design/build project because there are not a lot of those types of projects underway in Texas. The Texas Department of Transportation also would likely choose a design/bid/build process for I-35 construction, he said.

“The timing of the project is good in that we’re ahead of [I-]35 work, which may eat up the design/build market,” he said. “In contract, the design/bid/build that is the bread and butter of TxDOT, is heating up for them and they’re seeing more work in the coming years.”

In May, the agency began the developer procurement process, which takes about a year to complete, Word said. This process also will involve assessing which developer would best manage the risk of a design/build project. The agency likely will be more stringent in choosing a developer to avoid the issues and delays faced on the MoPac express lane project.

Under the design/build process, construction could begin in February 2019 with a project completion in May 2022.

Disclosure: Amy Ellsworth, general manager for Community Impact Newspaper's Round Rock-Pflugerville-Hutto edition, was appointed in February to the Central Texas Regional Mobility Authority board of directors, serving a two-year term through Jan. 31, 2019.