Converting the Orange Line busway into light rail would cost at least $1.2 billion and should not be pursued until ridership grows, according to a study by the Los Angeles County Metropolitan Transportation Authority.

Laying track, buying 60 trains and constructing a maintenance facility to store the cars for the 18-mile busway route linking North Hollywood to Chatsworth would carry a price tag of $1.2 billion to $1.7 billion. However, the conversion may be cost effective in the future, the report concluded.

“As the San Fernando Valley continues to grow and density is concentrated near transit, there will likely be a need for rail in the corridor in the longer term to ensure fast and convenient travel across the San Fernando Valley,” the report said.

Converting the Orange Line to light rail is supported by a number of elected officials and business groups, including the Valley Industry & Commerce Association, which is spearheading a campaign called Valley on Track.

Metro does not include an Orange Line light rail project in its long-range development plans. However, at the urging of area business and political leaders, Gov. Jerry Brown signed a bill last year that repealed 1991 legislation prohibiting above-ground, at-grade rail from crossing the San Fernando Valley.

The move paved the way for the Metro staff report on the costs. The planning and programming committee of the transportation authority is scheduled to discuss the report at its meeting on Wednesday. No action is expected to be taken.

Despite the report's recommendation against immediately proceeding with the conversion, VICA President Stuart Waldman said the advocacy group was pleased that the report found the costs of the project would be less than the first $2 billion "guesstimate" by Metro staff.

“This would be the only project that will get people out of their cars on the 101 (Freeway) and alleviate traffic,” Waldman said. “This is one step closer to making this a reality.”

Funding for the project would come from a ballot measure proposed for the next year to either hike the county sales tax to raise more than $100 billion for transportation projects or extend Measure R’s half-cent increase beyond 2039, when it will end unless further action is taken.

Measure R was a ballot initiative passed in 2008 , which promised $40 billion in new transit funding over 30 years. An initiative to extend it in November 2012 failed to win voter support by a slim margin.

“We are in a great position and feel good about this happening,” Waldman said.

The busway opened in October 2005 between North Hollywood and Warner Center and has proven to be one of Metro’s most heavily used routes. It averaged 16,360 weekday boardings its first month, a number that had grown to 29,722 average weekday boardings in February. That figure includes an extension that opened in 2012 connecting the Metrolink station in Chatsworth with Canoga Park.

The report found that operating a rail line between North Hollywood and Chatsworth would on average save riders about 15 minutes from the nearly hourlong bus commute. Operating and maintenance costs would range from $49 million to $73 million a year.

To continue service while tracks are being laid, Metro would need to offer either on-street replacement service or phase the conversion so only one segment of the busway is closed at a time, the report said.

The report also looked at improving Orange Line service but retaining it as a busway. That would require increasing crossing speeds, retiming traffic signals during peak travel hours and constructing grade separations at eight intersections. It also would require adding buses or using larger buses.

The cost for those improvements would range from $210 million to $350 million.