State officials say the proposed change could save $1 billion, as well as shave 30 miles off the trip. Other benefits include reduced tunneling and avoidance of newly discovered seismic dangers on the currently planned route.
However some see this as a desperate move in that has come very late in the game:
"Thursday's vote by the California High-Speed Rail Authority board ignited new political brush fires for an agency struggling to scrape together billions needed to complete the first 500-mile leg of the voter-approved system between the Bay Area and downtown Los Angeles' Union Station. Resurrecting consideration of an Interstate 5 route "is a step backwards," said Los Angeles County Supervisor Michael D. Antonovich, who represents Palmdale and pushed for that alignment when it was chosen several years ago."
Read more high-speed rail news at The Railist.