Tech heavyweights like Google, Apple and Uber are betting big on the future of driverless cars, but that reality may be years down the road. Coming sooner to a highway near you? Fleets of self-driving trucks.

That’s the premise behind the new startup Otto, founded by ex-Googlers Anthony Levandowski and Lior Ron. At Google, Levandowski led the self-driving car initiative while Ron is a veteran of Google Maps and Motorola.

Unlike Daimler, which last year announced plans for a new autonomous big rig, the company isn’t looking to reinvent the semi — instead it’s looking to retrofit existing trucks made since 2013. Its $30,000 retrofit kit will allow trucks to drive themselves on the highway, safely staying within a lane and maintaining a set speed, as well as slowing and stopping as needed.

Included in Otto’s $30,000 kit are cameras, radar, and Lidar sensors, as well as power steering and redundant braking systems. Real-time driving decisions are made by a customized computer.

Otto’s immediate goal isn’t removing drivers from the equation so much as providing assistance to them, letting a trucker take a needed sleep break while the rig drives autonomously, for example.

“Initially there will be certain roads that we know we can drive more safely,” Mr. Levandowski told The New York Times. “On those roads we’ll tell the driver, ‘You’re welcome to go take your nap or your break right now.’ If that’s 500 miles, that’s 10 hours, so he gets his full rest.”

Otto says that testing the technology is currently underway on highways with a research fleet, and they recently completed an autonomous demo of the tech on public highways in Nevada.