The Napa Valley Transportation Authority will pursue a plan to construct new traffic signals and add signal coordination to the stretch of Highway 29 that runs through American Canyon.

With that move, approved by the authority board Feb. 18, the agency will also shelve an alternate option that would have involved building up to six roundabouts to replace those signalized intersections.

American Canyon public works director Erica Ahmann Smithies said at the meeting that she supported the choice to move forward with the signal option and away from the roundabout plan.

She said the signalized option is lower-cost — around $58 million instead of $75 million for the roundabouts — and will be more straightforward to deliver, with less disruption for area businesses and private property owners.

An NVTA evaluation also found the signalized plan would improve the level of service on the corridor’s six intersections beyond what the roundabout option would achieve.

“Highway 29 is important for everyone in this valley,” Smithies said. “Its a connection to the broader Bay Area, and it’s exciting to re-imagine it as a continuous, technology-enabled transit corridor.”

NVTA officials expect the project — which the authority is pursuing in partnership with Caltrans and the city of American Canyon — will likely take 18 months to complete and construction is expected to begin in late 2029 or early 2030, following environmental clearance and project approval from Caltrans and a two-year design phase.

You can reach Staff Writer Edward Booth at 707-521-5281 or edward.booth@pressdemocrat.com.