Caltrans crews this week embarked on a four-month long project to repair a century-old bridge along Napa County’s state Highway 121.

The work along Highway 121, which is also known in the area as Monticello Road, will contribute to the preservation of the Capell Creek Bridge, whose original construction dates to 1907. The work will take place between Circle Oaks Drive and Longhorn Ridge Road. The project will consist of repairing cracks, road breaks and replacing the northwest wingwall.

The repair work requires crews to shift traffic for both directions of travel into a single northbound or southbound lane depending on the construction stages.

A one-way traffic signal system and temporary concrete barriers are being used to guide traffic into one lane for use by both directions of travel during the construction work.

Bicyclists are sharing the main traffic lanes with vehicular traffic within the project limits.