Napa County has chosen a fix for one of the North Bay's worst traffic choke points. On Oct. 21, the Napa Valley Transportation Authority board picked an "elevated direct connector ramp" as its preferred design for the intersection of Highway 29, Highway 12 and Airport Boulevard south of Napa.
How the flyover would work
Today, evening drivers on southbound Highway 29 who want to turn left onto Highway 12 toward Fairfield and Suisun City line up at a signal. The wait can top eight minutes, the Napa Valley Register reported. Under the chosen design, those drivers would move to the right, rise over Airport Boulevard and Highway 29 on a ramp, and merge onto eastbound Highway 12, the Press Democrat reported.
Westbound Highway 12 commuters heading toward Napa in the morning would not get a flyover but would get a second right-turn lane onto northbound 29. Traffic engineers say the design should cut rush-hour delays by about 90%, to roughly 55 seconds, the Register reported.
Cost and timing
- Cost estimates differ by outlet: the Register cited $81 million or more, and the Press Democrat reported $84 million to $94 million.
- The board rejected a cheaper "displaced left turn" and a pricier design that would raise Highway 29 over the whole intersection.
- More design work and funding are still needed. The Register said construction may not start until 2030 at the earliest.
Some board members worried the fix could push congestion to the nearby Highway 12 signal at North and South Kelly roads. "I think we need to give North Kelly/South Kelly a lot more thought," Napa Councilmember Bernie Narvaez said.