City engineers announced Sept. 25 that traffic over the Mare Island bridge will change to a permanent one-way westbound pattern starting Oct. 7 and continuing 24 hours a day through the bridge reconstruction project, scheduled to finish Jan. 5, 2027.

“This will be one way westbound all the time, through 24 hours a day, 7 days a week, through the completion of the project,” Sam Kumar, the city engineer on the project, told the joint City Council and school board 2x2 meeting. He said eastbound motorists should use State Route 37 as a detour.

City and school officials said the change followed stakeholder outreach, safety analysis and discussions with the school district after parents and school staff raised concerns about students arriving on time. The city said its analysis indicates the detour via Highway 37 will add only a few minutes for most drivers, and staff will monitor circulation and consider adjustments if problems arise.

Officials also said the bridge will be fully closed both directions Oct. 22 and Oct. 23 for in-water construction work. “October 22 and October 23 completely closed? Yes,” Kumar confirmed, adding the work will run from 6 a.m. to the end of the day on those dates.

City staff told the 2x2 that the public information team will release the traffic-change messaging and will provide a simple diagram for media and the public. “The media will have a very simple, common-man understanding diagram,” Kumar said in response to Council questions about outreach. Staff said the messaging would go out the next morning.

Officials said the city will allow two-way traffic for scheduled large events on specific weekends. The construction team and event organizers had already agreed to open the bridge to two-way traffic for the Maker Faire event scheduled on the weekend immediately before the circulation change.

The city said it had coordinated with police, neighborhood block captains and the school district during planning and that the project team will continue to solicit feedback after the October change to see whether additional tweaks are needed.

Public safety and school officials urged clear, early communications for parents and Mare Island residents. “We need to let Mare Island residents know, but also the parents of Leo Charter,” Mayor Andrea Sures said, asking about the communications timeline. City staff responded that the notices and map would be released the following day.

The city’s project timeline and the October full closures were presented as operational decisions by public works staff and not as formal votes by the council or the school board during the meeting.

Officials encouraged parents and commuters to review published detour maps and to plan alternate routes during the Oct. 22–23 closure and while the one-way circulation is in effect.