The crash happened along the westbound lanes of the 210 Freeway near Foothill Boulevard at around 1:30 a.m. Saturday. Caltrans had all lanes of the freeway closed except for the carpool lane for a construction project.
Investigators believe the driver, identified as 25-year-old Thomas Lapatka Jr., was speeding and under the influence when he slammed his 2010 Mercedes-Benz into a flashing arrow-board sign and then crashed into the rear of the patrol car.
The two officers and Lapatka were taken to an area hospital. All are expected to be OK. The officers were assisting with traffic at the construction zone at the time of the incident.
Authorities want to remind all drivers to slow down at cone zones.
"Any time you come up on one of those construction zones, be extra careful. Slow down, slow for that cone zone," said CHP Sgt. Chris Hamilton. "It is serious. We're out there working on foot. The Caltrans workers are working on foot. Things like this can happen even without alcohol included."
Lapatka was booked on suspicion of driving under the influence.