By next spring the Central Texas Regional Mobility Authority expects to hire a design firm to complete the plans to extend Toll 183A from Hero Way in Leander to SH 29 in Liberty Hill.
The agency’s board approved an authorization Nov. 8 to allow staff to begin the search process in late 2017 to hire a professional engineering firm.
After selecting a firm in the spring, final design work could begin once the project receives environmental clearance, expected for fall 2018. Design would be completed by fall 2019 and construction could begin after that. Schematic design, which is a high-level view of a project, began in late 2016.
Toll 183A Phase 1 opened in 2007 from RM 620 to New Hope Drive and nontolled frontage roads from RM 1431 to the south fork of the San Gabriel River. Phase 2 opened in 2012, expanding the toll facility about five miles north to Hero Way.
Phase 3 would add another 5.3 miles up to SH 29 and could open to the public in 2022.
Elements of the project would include up to three tolled lanes in each direction and a grade-separated interchange at SH 29 in which toll lanes would either go under or over SH 29, said Justin Word, the Mobility Authority’s director of engineering.
The project will be completed in a design-bid-build process, meaning design will be completely finished before any construction begins. The MoPac express lane project was completed under a design-build process in which construction began before the design was completed in an effort to expedite the process, Word said.
For Toll 183A Phase 3, it made more sense to do a design-bid-build process because the project is fairly straightforward, he said.