The chief spokeswoman for the state’s embattled high-speed rail project has announced she will be stepping down from her duties after 18 months on the job.

Since 2010, Rachel Wall has been the voice of the California High-Speed Rail Authority, the agency in charge of overseeing the $98 billion project to provide rail service between Los Angeles and San Francisco.

The project, which has ballooned in cost, has come under intense scrutiny recently, particularly from the California High-Speed Rail Peer Review Group, which released recommendations saying that state bond money should be withheld for the plan until a better business model is established.

Wall, whose last day at the authority will be Jan. 12, will be taking a position with Wal-Mart’s public affairs department.

wreisman@sfexaminer.com