DETROIT — General Motors isn’t promising that Ultra Cruise, its hands-free driving system for city streets, can handle every situation right away.

Ultra Cruise, which debuts in 2024 on the Cadillac Celestiq, will tell the driver to take over through roundabouts and other intersections requiring complicated maneuvers, said Jason Ditman, the system’s chief engineer. It also will relinquish control at the threshold of destinations such as a grocery store parking lot or the owner’s driveway, Ditman said.

“Over time, we’ll grow this to where we’re covering nearly every paved road,” he told reporters.

The limitations that GM is revealing for the system — and its repetition of the phrase “safely deploy” — show that the automaker is taking a different tack than Tesla, which is under investigation for accidents involving the semiautonomous features it calls Autopilot and Full Self-Driving. GM said Ultra Cruise can tackle 95 percent of driving scenarios.

Instead of just using cameras, as Tesla does, GM said its system combines seven long-range cameras with more than 20 sensors. It uses short- and long-range radar, lidar behind the windshield and a camera atop the steering column to monitor whether the driver is paying attention.

Ditman said GM has not begun testing Ultra Cruise on public roads but that the system will be fully vetted before its release, in contrast to Tesla’s reliance on its customers as Full Self-Driving beta testers.

“GM’s fundamental strategy for all ADAS features, including Ultra Cruise, is safely deploying these technologies,” Ditman said in a statement Tuesday. “A deep knowledge of what Ultra Cruise is capable of, along with the detailed picture provided by its sensors, will help us understand when Ultra Cruise can be engaged and when to hand control back to the driver. We believe consistent, clear operation can help build drivers’ confidence in Ultra Cruise.”

Ultra Cruise initially will be offered on high-end vehicles, Ditman said, while Super Cruise, which functions only on highways, has expanded to mass-market models such as the Chevrolet Silverado. Ultra Cruise will spread beyond the Celestiq — a $300,000 hand-built sedan — more quickly than GM rolled out Super Cruise to multiple vehicles, he said.

Because testing has not been completed, Ditman declined to specify exactly how much of Ultra Cruise would be enabled when Celestiq deliveries begin early next year.

“Whatever we have ready to safely deploy at that point in time will be on the car,” he said. “All the hardware will be there.”