The Texas Transportation Commission in the US approved issuance of a request for proposals (RFP) for a $120m design-build project for the Loop 1604 Western Expansion project in Northwest San Antonio.

The RFP will invite proposals from infrastructure development firms interested in the contract, which is expected to be executed in late 2013.

The new project will convert 4.7 miles of roadway between SH 16/Bandera Road and FM 471 into a four-lane, non-toll highway.

It will also build new bridge interchanges at Shaenfield, New Guilbeau and Braun roads with an option to complete development via the SH 151 interchange.

The project will improve mobility, traffic operations and safety by expanding Loop 1604 from a four-lane divided roadway into a four-lane expressway with continuous frontage roads.

"The new project will convert 4.7 miles of roadway between SH 16/Bandera Road and FM 471 into a four-lane, non-toll highway."

The Texas Department of Transportation (TxDOT) executive director Phil Wilson said that the new scheme brings the department one step closer to ease traffic in San Antonio.

"We pledge to continue utilising the local citizen input that has allowed the project to advance to this stage of development," Wilson said.

TxDOT received rights from the Texas Legislature to build up to three design-build transportation projects per year, which allows the department to contract with a single private sector provider for design and construction of transportation projects in excess of $50m.

TxDOT is responsible for maintaining 80,000 miles of road and for supporting aviation, rail and public transportation across the state.