Road crews are back at work repaving a bone-shaking stretch of Highway 101, one of the largest infrastructure projects in northern Sonoma County in 50 years.

The project, dubbed “the Big Pave” and expected to cost more than $155 million, will eventually smooth out a notoriously jarring 24-mile leg of the highway from Windsor to Cloverdale.

“I can remember traveling to Santa Rosa with my grandma and her complaining about how bumpy Highway 101 was,” said state Sen. Mike McGuire, D-Healdsburg. “Three generations of Sonoma County residents have had to endure teeth-rattling, shock-destroying conditions. The Big Pave is finally bringing much-needed relief.”

Work on the $74 million initial segment, encompassing 14 miles of roadway in both directions from Windsor to Geyserville, resumed last week after an eight-month suspension over the winter. Crews have begun repaving the highway’s southbound lanes from Geyserville to Healdsburg.

Commuters are still in for a jolt driving on Highway 101, despite work last year on the northbound lanes from Windsor to Geyserville and the southbound lanes from Healdsburg to Windsor. Orange signs in several spots along the newly paved segments warn drivers of bumpy conditions.

Temporary asphalt is in place on many of the roadway transitions from blacktop to concrete overpasses and back again.

Crews with Dublin-based DeSilva Gates Construction, the lead on the two-year contract, will soon dig up and replace those concrete slabs to create a gentler trip.

“They will make that final lift of concrete and remove those temporary tapers,” said Caltrans spokesman Bob Haus. “We should have things smoothed out by the end of July.”

Caltrans officials said the project is on schedule and on budget.

Much of the work is being conducted overnight to minimize traffic impacts, although some off-ramps will be closed through Saturday.

Those include the Central Healdsburg and Canyon Road exits, among others.

By September, a final round of paving will commence across the 14-mile initial segment, along with permanent lane striping and installation of raised reflective markers.

The attention then turns toward obtaining an estimated $80-plus million to start the project’s second phase — a 10-mile stretch between Geyserville and Cloverdale.

That section is not expected to get underway until 2020, and, like its predecessor, will likely be funded through dedicated transportation dollars from state and federal gas taxes.

“We’re still working on identifying the funding for the final phase,” said McGuire. “But for now, this season, we’re focused on completing the first phase of the Big Pave. I couldn’t be more excited that we’re about to hit the home stretch.”

You can reach Staff Writer Kevin Fixler at 707-521-5336 or at kevin.fixler@pressdemocrat.com. On Twitter @kfixler.