WASHINGTON (AP) _ President Clinton signed a $50 billion transportation bill into law Saturday, a wide-ranging measure funding transit and infrastructure projects, Amtrak and the Coast Guard.

The bill, for the fiscal year that began Oct. 1, includes $26.7 billion for highways, a 10 percent increase from last year, and $5.8 billion for mass transit programs.

``We believe these funding levels will allow us to make the substantial improvements in infrastructure and mass transit that are necessary,'' White House spokesman Jake Siewert said.

It also provides $571 million for Amtrak, including funds for a five-year plan to get the national passenger railroad operating self-sufficiently and eliminate the need for year-to-year subsidies.

It contains all the money Clinton requested for Coast Guard operating expenses, $2.8 billion, including search and rescue operations and increased spending for law enforcement and drug interdiction.

And it extends for one year a restraint on the government's use of new automobile fuel efficiency standards.