RTD hasn't brought its first FasTracks corridor back within its budget even after proposing a minimum of $113 million in controversial cuts, the transit agency's chief said Friday.

Cal Marsella, RTD's general manager, told elected officials and staff from Denver, Lakewood, Golden and Jefferson County that he is investigating other financing tools. Among them: asking cities and counties to put in more money to help fit the West Corridor light rail back into its $511.8 million budget limit.

RTD won't know how much more needs to be trimmed until it completes a cost review. It expects a final estimate for the West Corridor in August and won't publicly put a price tag on it until then.

The cost-cutting strategies used in the West Corridor will be applied to the other eight routes, RTD says, because it promised voters in 2004 that all the corridors would be treated equally.

"Commitments were made, but we have some financial realities here that have to be addressed," Marsella told the group at a meeting Friday morning.

Recent sharp spikes in construction costs and raw materials - such as copper, steel and cement - have forced RTD to re-examine the entire $4.7 billion program of rapid-transit projects.

The local officials pledged to work with RTD to get the project built, but without sacrificing the level of service that was promised.

The West Corridor is an 11.2-mile rail line from downtown Denver to Golden via Lakewood.

The most controversial change would leave Sheridan Boulevard north of 10th Avenue at-grade and build the rail line over it, instead of the other way around. That will save $7.5 million.

"This is a big change," Denver Councilman Rick Garcia said. "It's 180 degrees different than what was proposed."

Neighbors and local officials have balked at the change. They wanted to raise Sheridan Boulevard to improve drivers' sight lines and traffic flow.

Marsella said RTD would follow the original plan if local communities can find outside funding for the $7.5 million difference in cost. He said RTD would reimburse the cities or other parties of the project, scheduled to open in 2012, if it came in under budget.

The same strategy was used on the recently opened T-REX project, which came in under budget and allowed cities to be reimbursed for many of the upgrades they initially funded.

flynnk@RockyMountainNews.com or 303-954-5247