LOS ANGELES — The region famous for jilting the street car to take up a love affair with the automobile is trying to rekindle its long ago romance with commuter rail.

Los Angeles County voters agreed two years ago to pay a half-cent sales tax over the next 30 years to extend train and rapid bus lines, projects that would routinely require federal assistance.

If successful, the novel plan to borrow billions from the federal government, led by Los Angeles Mayor Antonio Villaraigosa, would result in the largest transit expansion project in the nation.

But the mayor, who sits on a county transportation board, wants a loan instead of Washington handouts to get the projects built in a decade rather than 30 years. He contends it would save money in the long run, result in more construction jobs and less traffic and pollution.

Under the so-called 30/10 initiative, the sales tax would generate about $5.8 billion over the next 10 years to pay for a dozen projects.

Local transportation officials said another $8.8 billion is needed to pay for the estimated $14.6 billion total cost. By using the future sales tax revenue as collateral for long-term bonds and a low-interest federal loan, the county Metropolitan Transportation Authority could put these projects on the fast track. The county would repay the federal loan over 20 years with proceeds from the sales tax.

The projects include a long-awaited subway extension to the economically vibrant west side of Los Angeles (a plan often called the Subway to the Sea), a regional connector linking three rail lines in the downtown core, plus light rail extensions reaching Los Angeles International Airport and communities to the south and east. In all, completion of these projects would add 78 miles of rail and bus-only lanes to the current, 102-mile system and 77 million annual transit boardings to the MTA’s current 445 million. Read more at www.huffingtonpost.com