SAN RAMON -- Transportation officials will host an open house Thursday to explain plans to install Contra Costa County's first toll lane on Interstate 680 in the San Ramon Valley.

The Bay Area Toll Authority and Caltrans are preparing to convert the Interstate 680 carpool lane into an express lane from Rudgear Road in Walnut Creek to Alcosta Boulevard in San Ramon.

It will remain free for buses and carpoolers, but solo drivers can opt to use the lane for a fee paid through an electronic tolling device known as FasTrak. A similar express lane operates on Interstate 680 over the Sunol Grade.

The open house will be held from 5:30-7:30 p.m. at the San Ramon Community Center, 12501 Alcosta Blvd.

Residents can review project plans and information, talk with project team members and provide input. Individuals may also see project details and make comments about the project online at www.baifaexpresslanes.org.