The East Sonora Bypass is planned to open to drivers Nov. 1.
The California Department of Transportation will hold a ribbon-cutting ceremony on the new, second phase of the Highway 108 project at 1 p.m. that day at the bypass' east end.
Caltrans contractors have been working on the project since May 2012, with the original timeline looking at completion in April 2014.
The ceremony will be open to the public and held at the eastern end of the bypass, which will route Highway 108 motorists on a new thoroughfare between Peaceful Oak Road and Via Este Road.
Caltrans spokeswoman Angela DaPrato said on Tuesday that the event will be a "true ribbon cutting," meaning traffic will open on the bypass after the ceremony. Construction has been backing up traffic on Highway 108 for weeks as crews work to wrap up the project.
DaPrato said that the construction teams are trying to finish all work on the bypass by the Nov. 1 open date, including cosmetic and landscaping work unrelated to the road itself.
"They're trying to wrap up all minor details," she said. "That is the intention and the goal, to get everything wrapped up. Could there be some minor landscaping work or little things they need to work on that won't affect motorists? Maybe."
This phase, when complete, will include a partial interchange at Peaceful Oak, a grade separation at Mono Way and a frontage road. The bypass extension will have two elevated stretches, rising 100 to 110 feet above Mono Way and 50 to 60 feet above Peaceful Oak.
According to state traffic data, an average of 22,300 vehicles pass along Highway 108 on the existing bypass every day. During peak summer months, that average goes up to about 24,600. The stretch passing through East Sonora is the heaviest travelled section of Highway 108 outside of the busiest part in Modesto, which includes McHenry Boulevard, according to state traffic statistics from 2011.
The project was contracted last year to Teichert/MCM Construction. It is the second of three phases that transportation officials say will eventually make up a highway running from Sanguinetti Road in Sonora to the four-lane stretch at Soulsbyville. The state announced in 2006 that Phase 2 was fully funded and set for construction to run from 2010 through 2012.
However, state funding issues stalled the project before officials were able to find available funds from multiple sources.
Money was secured through the Proposition 1B-created Corridor Mobility Improvement Account and a 2006 voter-approved transportation bond measure. But not before a few cutbacks led to a redesign, with the updated plan excluding two entrance and exit ramps. State and local planners have said they will try to find funding to add those ramps after the second phase.
No funding source or timeline has been identified so far for the project's third phase.