A state Assembly bill aimed at creating six additional lanes in the next decade on Interstate 15 between Lake Elsinore and Corona has cleared a significant hurdle and now awaits Senate approval.

The bill, AB 1954, by Assemblyman Kevin Jeffries, R-Murrieta, received unanimous approval from the Assembly at the end of May and is expected to go before the state Senate within the next three weeks, Jeffries said.

The bill would allow for the construction of one lane open to drivers at no cost in each direction in what is now the median on I-15 between Highway 74 in Lake Elsinore and Highway 91 in Corona. Also, the bill would provide for two toll lanes in each direction along that segment of I-15.

"We're very happy with the way the legislating process is going," said John Standiford, spokesman for the Riverside County Transportation Commission, which initiated the bill's drafting. "But there's still a lot of work to go through."

The free lanes would be funded by revenue from a half-cent sales tax, approved by California voters in 2002, which is expected to generate as much as $950 million over 30 years.

Fees charged on the toll lanes would offset the full cost of building those four lanes, which is estimated at $1.1 billion, Standiford said. Standiford said it could take 50 years for the tolls to fully pay off the construction costs, at which time the lanes could become free to use. The lanes will be free for carpools with three or more people per vehicle.

"I think anyone who commutes on that road over the last five years has seen a significant increase in traffic and our county's not going to get any smaller," said Lake Elsinore Councilman Bob Magee, who represents the city on the transportation commission representative. "This will literally double the capacity on our road system."

Pending Senate approval and an environmental review, construction is targeted for completion by 2017 or 2018, Standiford said.

Before that project gets under way, however, transportation authorities in each county aim to begin construction creating toll lanes on Highway 91 from I-15 to hook up with the toll lanes already in use in Orange County. That segment carries more than 300,000 motorists daily, including many heading up I-15 en route to Orange County.

The Highway 91 project adds toll lanes from I-15 into Orange County, and is being orchestrated by the Orange County Transportation Authority.

"In many ways, we feel we need to complete the 91 first so the added capacity would have somewhere to go," Standiford said.

The bill's progress so far is an indication that the Legislature has become more interested in expanding the state's beleaguered transportation system, Jeffries said.

"It's taking a toll on the infrastructure from the growth we've encountered in the state," Jeffries said. "Toll roads are the only way we can pour concrete and add more lanes."

Contact staff writer Nelsy Rodriguez at (951) 676-4315, Ext. 2626, or nrodriguez@californian.com.