The draft rail plan calls for investing billions of dollars in track improvements for those Amtrak lines, as well as increasing the number of trains on the routes.

On the San Joaquin line through Fresno, that means "at least two additional trips per day in the near term," Ogden said.

But the number -- and speed -- of conventional Amtrak trains could ramp up considerably once the first high-speed rail construction section is completed between Madera and Bakersfield.

Now, the top speed for Amtrak trains in the San Joaquin Valley is 79 mph, with an average speed of 53 mph between Sacramento and Bakersfield.

Other features of the draft rail plan include the potential to add new intercity rail routes and extensions of existing Amtrak routes.

Those include possibly extending the San Joaquin line north of Sacramento to Redding, and extending the Capital Corridor service southwest to Salinas and east to Reno.

Among the new routes discussed are a proposed Amtrak Coast Daylight train to connect San Francisco, San Jose and Salinas through San Luis Obispo to Los Angeles, and a Coachella Valley line from Los Angeles to Palm Springs and Indio in Riverside County.

The plan also describes the proposed X Train, a privately backed high-speed train between Las Vegas and Fullerton.

Following the public comment period that ends March 11, a final version of the plan is expected in June.

Caltrans is writing the plan to comply with a 2008 federal law that requires states to develop plans, and update them at least every five years, to qualify for federal money for high-speed rail and intercity passenger train systems.

The Obama administration has awarded California more than $4.2 billion for intercity rail projects, including more than $3 billion to start building the state's high-speed system in the Valley.

Under state law, Caltrans must update its rail plan every two years to address both passenger and freight rail needs over a 10-year span.

"It sounds like we're doing plan after plan after plan, but the reality is that things are changing so fast in the rail arena that we have to keep up with what's happening," Ogden said.

Caltrans offers several ways for people to comment on the draft of the California State Rail Plan (which can be viewed at californiastaterailplan.com):

Online at californiastaterailplan.com/contact

By mail to Caltrans Division of Rail, Office of Planning and Policy, 1120 N St., MS 74, Sacramento, CA 95814

By email to CSRP@dot.ca.gov

Comments on the draft plan are due by March 11.