Plans for a new transit line connecting the Westside of Los Angeles to the San Fernando Valley are moving forward, and Metro has narrowed possible routes and modes of travel for the project down to six distinct options.

They include multiple routes for both light and heavy rail trains, as well as another concept that would put a monorail or rubber-tired tramway alongside the 405 freeway as it winds through the Sepulveda Pass.

Each possible light or heavy rail concept would require construction of a long tunnel beneath the Santa Monica Mountains, since the trains would not be able to navigate the steep grade of the pass itself.

That’s one reason Metro is giving serious consideration to a monorail option recommended last year by Los Angeles Mayor and Metro board chair Eric Garcetti.

A monorail system, familiar to visitors of Disneyland and the Las Vegas Strip, could better handle the elevation gain of the Sepulveda Pass than traditional light or heavy rail trains. So could a rubber-tired transit line, similar to those found in Paris and Mexico City.

According to Metro, the latter option would also provide the most capacity for riders, but would also be one of the least energy efficient possibilities.

The speediest option would be heavy rail, which could be constructed as a new transit line or as an extension of the Purple Line, which is set to begin traveling from Downtown LA to Westwood in 2026 (it now ends in Koreatown).

Metro spokesperson Dave Sotero tells Curbed that a cost-assessment hasn’t yet been completed for any of the options. A feasibility study examining each possibility in greater detail will be ready next year.

Where would the new transit line go? Each option being considered would connect the Valley’s Orange Line to the Purple Line in Westwood, as well as the Expo Line—at either the Expo/Sepulveda or Expo/Bundy stop. The 10- to 14-mile route wouldn’t have many stops. Its primary function would be to connect other transit lines and to provide commuters with an alternative to the traffic-clogged 405 freeway.

Metro estimates that more than 400,000 vehicles travel through the Sepulveda Pass every weekday, yet less than 2 percent of commuters making the trip use public transit.

“There’s a lot of opportunity there,” says Sotero.

Eventually, Metro plans to build a second portion of the project, which would connect the transit line to LAX. But for now, the agency is only considering options for the first leg of the project.

That phase is now scheduled for completion in 2033, though it’s one of the 28 projects that the agency aims to open in time for the 2028 Olympic Games. The only way that’s likely to happen is through a partnership with a private company that would shoulder much of the construction cost.

The agency has already received at least two proposals for a public private partnership on the Sepulveda Pass project.

Metro will hold the last of three community meetings about the project Tuesday evening in Westchester.