Toyota's first Level-4 autonomous vehicles - that is, self-driving cars that are capable of fully autonomous operation within a defined area of operation - will first appear in commercial applications, the automaker confirmed this week. The Japanese automaker feels that is a necessary first step before its self-driving technology is ready for privately owned passenger vehicles.

Ford and other automakers are taking a similar approach, introducing full autonomy to taxis and delivery vehicles in advance of making the technology available to individual consumers. The technology required for fully autonomous vehicle operation is expensive and resource-intensive, and until automakers have every last kink ironed out, limiting Level-4 autonomous cars to commercial cars will allow automakers to limit the potentially messy repercussions of a still-developing technology.

Specifically, Toyota is targeting services like on-demand ride services, mobile shops, and ambulances to utilize its self-driving tech before that technology reaches the consumer market. According to James Kuffner, head of Toyota Research Institute-Advanced Development (TRI-AD), the operators of these fleets will be able to oversee maintenance and control their deployment, Reuters reports.

"It will take more time to achieve Level 4 for a personally owned vehicle," Kuffner says. "Level 4 is really what we are striving for to first appear in mobility as a service."

Besides Toyota's own efforts to develop self-driving technology, it was announced in 2018 that the automaker would partner with Uber, using the ride service provider's autonomous vehicle technology in a fleet of Toyota Sienna minivans set to hit the street in 2021.

Meanwhile, Toyota's first Level-2 autonomous vehicle - a car capable of piloting itself on the highway, with both acceleration/deceleration and steering fully automated - will launch in 2020. Many competing automakers already have such systems in production.

The Society of Automotive Engineers (SAE), which established and defined the various levels of vehicle autonomy in 2016, describes one level above the sort of autonomy Toyota and most other automakers are currently striving for: Level 5. That's a level in which the self-driving vehicle is expected to perform all aspects of driving all the time, regardless of conditions or location, and it's much further off than Level 4, requiring the car to be able to navigate even areas that aren't already pre-mapped.