When Caltrans started the nightly Webster Tube closures on April 6, 2026, it said they would last "approximately 6 months." Six months from April 6 runs into early October. The project's September 11 newsletter still lists "Webster Tube work continues Sundays to Thursdays from 10PM to 5AM." It gives no end date. Through the end of September, neither Caltrans' project updates nor Alameda CTC's traffic advisories had posted anything newer.
Living near Marina Village, it's easy to treat the Oakland Alameda Access Project as a series of detours to wait out. The project documents show more than that. The tube work is being paired with new walking, biking and boat options, and most of them are in or near west Alameda. A new walking and biking path is being built on Mariner Square Loop, right where the tubes come out in Alameda. The free water shuttle to Jack London Square leaves from Bohol Circle Immigrant Park, a short distance along the shore. Its expanded schedule is paid for by construction-impact money sized to the 19 months of tube work. How easy your next year of crossings is may depend on how well you know these options before the Posey Tube phase begins.
Where each crossing stands as of late September
| Crossing | What's happening now |
|---|---|
| Webster Tube, Oakland to Alameda | Fully closed 10 p.m. to 5 a.m., Sunday through Thursday, since April 6. New walking and biking path built but not finished |
| Posey Tube, Alameda to Oakland | Open to drivers, pedestrians and cyclists while the Webster Tube is closed. Its own construction phase is expected in early 2027 |
| Park Street Bridge | Caltrans' advised alternate route during Webster closures |
| Oakland Alameda Water Shuttle | Free, Tuesday through Sunday, from Bohol Circle Immigrant Park to the foot of Broadway |
| Alameda Seaplane ferry to San Francisco | $5.10 one-way adult fare, effective July 1, 2026 |
When the Webster Tube is closed for the night, the posted detour for drivers heading into Alameda runs south on I-880 to 23rd Street, across the Park Street Bridge, then along Lincoln Avenue. For anyone coming home to Marina Village late on a weeknight, that means approaching from the east side of the island instead of coming straight out by Mariner Square. Caltrans' project toolkit says the two tubes will not be closed at the same time and that pedestrian and bicycle access will be maintained.
Buses are affected too. AC Transit lists Lines 19, 30, 51A, 96, O and 851 as detouring around the Webster Tube on their Alameda-bound trips after 10 p.m., Sunday through Thursday. The closures used to be planned to end at 6 a.m. The Alameda Post reported in February that Caltrans agreed to reopen at 5 a.m. instead, so early trips on Lines 30 and 51A would not need to detour. That same report described how the original plan for continuous daytime single-lane Webster closures was dropped. An earlier closure plan from April 2025 still turns up in searches, and it no longer reflects what Caltrans is doing.
The new path at Mariner Square Loop
The piece of the project closest to Marina Village is a new path. In its September newsletter, Caltrans said the new bicycle and pedestrian path inside the Webster Tube "is built, but work is not yet complete." Crews were expected to start installing railings "over the next few weeks." Outside the tube, the connecting paths near Mariner Square Loop and the link to 4th Street were described as "nearing completion."
On Mariner Square Loop itself, crews were upgrading street lighting, finishing concrete bases, adding temporary striping and laying underground conduit. Caltrans says the finished stretch "will become the new bicycle and pedestrian pathway connecting the Alameda side to and from the Webster Tube." Inside the Webster Tube, Caltrans describes a protected path shared by pedestrians and cyclists, "not a designated bike lane." The project's Alameda map shows the widened walkway continuing along Webster Street to Mariner Square Loop, along with a new Class II bike lane on Mariner Square Loop and sidewalk extensions on Mariner Square Loop and Mariner Square Drive.
The September newsletter does not give an opening date. Until it says the path is open, assume it isn't. Once it is, people walking or biking will have a route through the Webster Tube between Oakland and Alameda that comes out next to Marina Village.
Early 2027: the Posey Tube's turn
For Marina Village, the Webster Tube closures mostly affect the trip home. The next phase affects the trip out. In a May 2026 report, the City of Alameda described what follows the Webster weeknight closures as "limited weekend full closures and an extended single lane closure in the Posey Tube," starting in early 2027. The report also said "West Alameda is expected to be most affected by these construction closures." The Posey Tube's Alameda entrance sits near Marina Village Parkway and Mariner Square Drive. AC Transit's Line 19 stops there.
The details aren't set yet. Caltrans' September newsletter says it is working with Oakland, Alameda and Alameda CTC on "determining the timing and type of closures" for the Posey Tube and the Jackson Street off-ramp. It also says "the remaining work has different construction and safety needs." No dates, lane counts or weekend lengths had been published by the end of September. The posted detour for a Posey closure runs along Lincoln Avenue, across the Park Street Bridge and onto northbound I-880 at Oak Street. Caltrans' toolkit says detours are mandatory whenever a tube is closed.
The disruption has a payoff. The finished project includes a new dedicated on-ramp, called "the horseshoe," that connects the Posey Tube directly to I-880. Caltrans' current schedule has overall construction running from early 2026 to spring 2029.
A boat funded for the construction years
The water shuttle, a boat named Woodstock, is the option most directly tied to the construction. The City secured $931,000 from Alameda CTC to add service on top of the baseline five-day schedule "for the anticipated 19 months of construction in the Webster and Posey Tubes." That money began paying for expanded service in March 2026. Under the Phase 2 plan, service runs six days a week, Tuesday through Sunday, with longer weekend hours, from July 2026 through October 2027. From November 2027 through June 2028 it drops to five days, Wednesday through Sunday. Tuesday service would continue only if funding allows.
Demand has grown along with the schedule. Weekly trips rose from 187 at launch to 345, an increase of 84%. Through May 2026, Woodstock had carried more than 236,000 passengers and 56,000 bicycles. May 2026 was its busiest day, week and month so far.
Practical details from the City's shuttle page:
- Alameda dock: Bohol Circle Immigrant Park, at the north end of Fifth Street near Target
- Oakland dock: the foot of Broadway in Jack London Square, just west of Scott's Restaurant
- Hours: about 7 a.m. to 7 p.m. Tuesday through Thursday, and about 7 a.m. to 9:30 p.m. Friday through Sunday. No service Mondays
- Capacity: 31 passengers and 14 bikes, including cargo bikes. Everyone gets off at the end of each trip
- Parking: a small public lot on Tradewind Drive with 34 standard and two ADA spaces, limited to four hours. Twelve Bike Link lockers sit by the park's playground
- Pets: only in an enclosed carrier that fits on your lap. Trained service animals are allowed
- Alerts: SF Bay Ferry's BayAlerts, under "Route OAS"
On the Oakland side, the Jack London Square dock is less than a block from SF Bay Ferry's Oakland terminal and close to the Amtrak station. If you miss the last boat, AC Transit Line 96 stops on Mitchell Avenue behind Target. In Oakland, you can catch it at 7th and Franklin.
What's still only proposed
Two other options come up often, and neither exists yet. City staff have proposed a West Alameda Bay Wheels pilot for 2027 to 2029. It would have eight docking stations and 53 e-bikes to connect riders to the shuttle, ferry, buses and local destinations during Posey Tube construction. The stated purpose is to make the shuttle more useful for trips to Alameda Point businesses, the Webster Street business district, Marina Village offices and the College of Alameda. It is a staff proposal. Nothing is operating.
The Oakland–Alameda Estuary Bridge for people walking and biking is still listed as in its planning phase on the City's project page. A June 2024 project study report compared three design options and estimated capital cost at $303 million in escalated dollars. That figure is a planning estimate. It does not mean a design has been chosen or construction funded. For the years the tubes are under construction, the Webster Tube walkway and the shuttle dock at Bohol Circle are what Marina Village has to work with.
If the tube schedule is part of your thinking about when to list or buy in west Alameda, Ben Wahli and the team can walk you through how the construction timeline lines up with your plans. Request a Free Home Valuation to get started.
