Steve Mitgang occasionally sits down with commercial truck drivers for coffee, asking them what they think of having video cameras in the cab to monitor their driving.

“They feel like in the next few days or months, there’s going to be a passenger vehicle that is going to strike them, and they are going to be falsely accused for that incident,” said Mitgang, chief executive of San Diego’s SmartDrive Systems, which makes video-based telematics. “Post-crash litigation as related to commercial transport is out of control.”

That sentiment highlights why there’s a growing acceptance of onboard video in commercial truck fleets to help reduce liability, cut fuel costs and train drivers to be safer on the road.

The two market leaders in video monitoring of commercial truck fleets are based in San Diego — SmartDrive Systems and Lytx, the maker of DriveCam. Both privately held companies posted significant growth last year as more transportation firms adopt video-based telematics. These subscription services use onboard video and software to not only document what happened in crashes but also pinpoint bad driving habits such as speeding, hard braking or rapid acceleration.

“Over the last two years, the market has really turned in the direction where everybody recognizes the value of clouded connected cameras on vehicles, particularly commercial vehicles,” said Brandon Nixon, chief executive of Lytx.

Besides video, Lytx and SmartDrive also collect reams of sensor data from trucks and their surroundings — giving them a rich situational database of the interplay between vehicles on the road.

The market is getting more competitive, but SmartDrive Systems, which has raised $150 million in capital since it was founded in 2004, said it posted 94 percent year-over-year subscription growth last year and nearly 400 percent growth over the past three years.

Lytx is bigger and was bought a year ago by Chicago private equity firm GTCR for more than $500 million. It booked 101,000 new subscriptions to its DriveCam video system last year, bringing its total commercial fleet install base to more than 400,000 vehicles.

The adoption of video in commercial trucks is being driven by fleet operators and insurance companies trying to manage risk. “The customer that SmartDrive and Lytx have tend to operate really heavy vehicles or they are transporting people,” said Clem Driscoll of C.J. Driscoll & Associates. “So in either case if they get in an accident, there is going to be damage and there is going to be potential liability.”