PHOENIX (AP) The U.S. Department of Transportation has granted an additional $638 million to complete a light rail extension project in Phoenix.

Democratic Sen. Kyrsten Sinema said in a press release that the South Central light rail extension will help the state's economy and create jobs.

The project will receive $530 million from the Federal Transit Administration's Capital Investment Grants Program and $108 million from the Federal Highway Administration.

The rail extension is expected to cost a total of roughly $1 billion, according to reports. The project previously received two $100 million federal grants in July 2019 and in May.

The 5.5-mi. (9-km) extension will connect with existing tracks that run from downtown to south Phoenix. The project is expected to be completed in 2024.

Sinema and Democratic Sen. Mark Kelly said in a statement that 38 percent of the residents in South Phoenix live below the poverty line and 12 percent of households in the area do not own a vehicle.

"By connecting South Phoenix with the rest of the Valley Metro light rail, this project will give folks a reliable transportation option and increase economic opportunity," Kelly said in the statement.

The project had been approved by the federal government in April 2019.

A proposition to block construction of the rail extension was overwhelmingly rejected by voters in August 2019.