Another commuter rail line appears headed for North Texas.

The Federal Transit Administration gave the okay in March to start preliminary engineering and design for TEXRail, a proposed $758 million commuter line along 37 miles of the Cotton Belt corridor stretching from far Southwest Fort Worth to Dallas/Fort Worth International Airport.

TEX Rail would join two other area commuter lines – Trinity Railway Express and Denton A-Train – in the Southwest’s fastest growing passenger rail market.

The FTA notified the Fort Worth Transportation Authority by letter dated March 23 that it had given the go-ahead. The T, however, must secure a federal grant for about half the project’s cost before dirt can move. The North Central Texas Council of Governments is seeking additional public and private funds for the project.

TEX Rail, if approved, could begin service by 2016.