The Japanese automaker envisions servers constantly collecting data on a car’s position to predict the vehicle’s course up to roughly 10 seconds down the road.

These predictions are fed back to the car and used to control speed and direction if the data connection is interrupted, people familiar with company’s plans said.

When there are long data interruptions, the car will slow down and have limited navigation within the range of onboard sensors.

The more vehicle data the system can collect, the better its predictions will be. Subaru will seek to bring other automakers on board through licensing deals and other agreements.

The maker of the Legacy and the Outback is experimenting with a version of the system on a test track using a 4G-enabled vehicle.

Autonomous driving is one of the fiercest areas of competition for global automakers. Tesla offers an Autopilot feature and is testing more ambitious full self-driving software, which allows vehicles to switch lanes and park autonomously. But CEO Elon Musk recently said the company would not receive regulatory approval this year for cars can be driven without someone behind the wheel.

Self-driving vehicles remain few and far between on roads. But as autonomous technology moves to higher levels, the danger posed by a loss of data connection increases. At Level 3 on a scale of zero to 5, a self-driving car can perform many operations without a human behind the wheel in normal conditions.

When Japanese telecom KDDI suffered a days-long wireless network outage in July, connected cars made by Toyota Motor and other automakers were disrupted.

Honda Motor and others have sought to guard against this risk with technology that uses backup data connections – a feature that adds to costs.

Subaru offers automatic braking and other driver assistance features on cars with the EyeSight system, which made its debut in 2008.