Caltrans is set to open a new mile-long bike path between Olompali State Park and the Redwood Landfill interchange on Friday. The opening marks the last piece of Marin County’s year-and-a-half-long construction project in the Sonoma-Marin Narrows section of Highway 101.

Two projects in the area between Novato and the county line extended the northbound carpool lane, improved the landfill interchange and added frontage roads and bike paths.

With the opening of the new path, cyclists can ride from Novato to Petaluma along paths and bike lanes mostly following Highway 101. From Atherton Avenue in Novato, bike lanes on Redwood Boulevard extend to the entrance of Olompali Park. From there, the new bike path fronts the west side of Highway 101 to the landfill interchange.

A new extension of San Antonio Road with a bike path extends from the interchange to the county line. On the Sonoma County side, construction is underway on a project to build a new highway bridge over San Antonio Creek and add frontage roads to Petaluma. When complete in 2017, that project will connect the bike path and lane system from the county line to Petaluma.

Currently, cyclists continuing north to Petaluma from the county line can ride along San Antonio Road to I Street or D Street to Petaluma.