The state Senate approved a bill Thursday that would require underground construction of any rail line built in residential areas of North Hollywood and Van Nuys.
The measure, approved 21 to 7, was introduced at the behest of east San Fernando Valley homeowners living along a proposed rail route that parallels Chandler and Victory boulevards.
The Assembly Transportation Committee is scheduled to consider the measure April 3.
The bill, introduced by state Sen. Alan Robbins (D-Tarzana), is similar to one approved by the Legislature last year but vetoed by then-Gov. George Deukmejian, who said it was a local issue that should not be decided in Sacramento.
A spokesman for Gov. Pete Wilson said the new governor has not taken a position on the bill.
Homeowners along the proposed rail route, which follows Southern Pacific railroad's Burbank Branch right of way from North Hollywood to Warner Center, say they hope that the bill will become law to allay their fears about noise from ground-level trains.
Last March, the Los Angeles County Transportation Commission voted to extend the downtown-to-North Hollywood Metro Rail subway westward along the little-used freight right of way, keeping the line underground in all residential areas.
But because construction is not scheduled to begin until 1996, and the line is not expected to be completed to Warner Center before 2008, homeowners fear that cash shortages in the future might tempt commissioners to build the line aboveground, which would cut the cost by about half.
The line "would be a disaster if built at ground level," Robbins told the Senate, because some bedrooms lie within 12 feet of the right of way.
In a reference to a rival rail plan that is being studied by the county Transportation Commission, Robbins argued that his bill "is in no way an anti-monorail bill."
Despite the vote last March for the Metro Rail extension along the Southern Pacific route, commissioners have not ruled out the possibility of substituting a monorail or magnetic-levitation line in the median of the Ventura Freeway from Universal City to Warner Center.
A recently released commission study found that the proposed 16.2-mile monorail or magnetic-levitation line in the freeway median would cost $2.3 billion, while the 14-mile North Hollywood-to-Warner Center Metro Rail extension would cost $2.7 billion.
In a brief debate before Thursday's vote, several senators said they opposed the bill because it would reduce the county Transportation Commission's flexibility in determining what kind of line to build.
And state Sen. Art Torres (D-Los Angeles) argued against passage because of the high cost of tunneling, saying it "could rob us of all the money" needed for building a line in his San Gabriel Valley district.