The Federal Railroad Administration sent $21 million to Caltrans on Friday to begin environmental reviews and preliminary engineering on three projects that should speed up passenger rail service through San Diego County.

Because several stretches of the rail corridor have only a single track, Amtrak and Metrolink trains must often grind to halt on their way in and out of San Diego while they wait for another train to pass.

After the three projects that received start-up funding are finished, there would be stretch of more than 10 miles of double track, according to an FRA press release.

The grants were initially announced last year, but the funding was not released until now.

Caltrans public affairs officials were not available to provide comment on the timeline of the work or how much additional funding would be needed to complete the projects because of they remain in crisis mode after a Caltrans worker in San Diego had his arm cut off on Thursday.

FRA spokesman Mike England said more grants could be announced next week. He also said the FRA still had pots of money to tap into to fund rail and track construction.

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