Crews successfully completed their tunneling operation

MONTEREY COUNTY — Caltrans announced that it had called in a heavy-lift helicopter on Tuesday, Jun. 22, to remove tunneling equipment which had been instrumental in the installation of a 10 ft. diameter, 1.25-inch-thick steel pipe culvert beneath the roadway.

Late last week, crews successfully completed their tunneling operation from the east side of Rat Creek Canyon, through the fill underneath the roadway, and broke through where the culvert will outlet on the coast side of Highway 1.

This tunneling operation successfully installed the 10-foot diameter steel pipe culvert at a 30 percent slope, and it will serve as the centerpiece of redundant drainage infrastructure at Rat Creek, which will substantially improve water flow capacity during future storm events.


Papich Construction and Caltrans engineers determined that tunneling the main culvert instead of installing it during the fill construction would allow for the reopening of the roadway 4 to 6 weeks earlier than originally planned. The roadway was successfully reopened just 86 days after a late January storm event and associated debris flows severed this scenic stretch of coastal highway.

Once the tunneling machinery had performed its task, it was broken into two segments, each weighing some 25,000 pounds. The helicopter made two lifts, and the equipment was placed on the side of the highway where it will be transported off-site.

Highway 1 at Rat Creek will remain open as final construction work wraps up in late summer. Motorists can expect intermittent reversing lane closures with delays of up to 10 minutes through this still active construction zone.

Caltrans reminds motorists to move over and slow down when driving through highway work zones.

For traffic updates on other state highways in Monterey County, travelers may contact Caltrans District 5 Public Affairs at (805)549-3318 or can visit the District 5 website at