Caltrans predicts that building a roundabout-featuring fix for congested Soscol Junction where Highway 29 and Highway 221 meet east of the Grapecrusher statue could all but erase rush-hour delays there.
Delays at the signalized intersection with no changes will top five minutes in 2025. Delays with the project in place will be eight to 15 seconds, a new state report said.
By 2045, delays could top seven minutes if the intersection remains as is. But vehicles could navigate a new, improved Soscol Junction in eight seconds to 17 seconds.
No roundabouts would be built on Highway 29 itself. Rather, Highway 29 would be elevated over Highway 221/Soscol Ferry Road, allowing traffic to flow without stopping for red lights.
Two roundabouts would be on Highway 221/Soscol Ferry Road on each side of the new overpass. They would regulate traffic entering and leaving Highway 29 and through traffic passing underneath it.
“The purpose of the proposed project is to alleviate congestion between Napa Valley and the Fairfield/Vallejo areas and improve operations,” the report said.
If Caltrans is correct, the Soscol Junction project would solve the problem at this particular intersection for decades to come.
A Napa Valley Transportation Authority (NVTA) project list shows work starting at the intersection of Highway 29 and Highway 221/Soscol Ferry Road as soon as 2022.
A milestone recently happened when Caltrans released the draft environmental document for the project. Those 450 pages give perhaps the clearest picture yet of the proposed Soscol Junction.
For example, the document describes how the estimated $36 million project would be built over two years.
About 140,000 cubic yards of soil needs to be moved around, enough to fill 10,000 commercial pickup trucks. Excavators, cranes, loaders, portable generators, air compressors and temporary traffic signals will be on the scene.
At one point during the five-phase construction, southbound Highway 221 traffic wanting to turn onto southbound Highway 29 toward American Canyon will be detoured. Vehicles will travel through a nearby business park using Napa Valley Corporate Drive to connect with southbound Highway 29.
At another point, northbound Highway 29 traffic wanting to turn onto northbound Highway 221 toward the city of Napa will take the long way around. Vehicles will use Airport Road, Devlin Road and Soscol Ferry Road to make the connection.
A temporary sound wall could be erected along Soscol Ferry Road during construction and removed when the project is completed.
The finished Soscol Junction will have a path to encourage people to walk and bicycle. The existing intersection has no bike/pedestrian path. High speeds from vehicles create a high level of stress for cyclists and pedestrians, the study said.
Go to https://bit.ly/2LIkL2c to see the proposed mitigated declaration for Soscol Junction. Go to https://bit.ly/35240GY to see an animated video of how the proposed Soscol Junction is supposed to operate.
People can comment on the environmental during a meeting from 5:30 to 7:30 p.m. Tuesday at the NVTA offices, 625 Burnell St., Napa.
“Caltrans welcomes all and any questions about the project in general and the document,” agency spokesperson Janis Mara said. “The event is more of an open house, with display boards of the project; there will also be presentations and time to ask questions and get answers.”