On Christmas Eve, the United States Patent and Trademark Office released a patent application from Toyota for something called a “car wash judgement system”. It seems to be a system allowing future autonomous cars drive themselves to a car wash when they’re in need of a cleaning. Sounds wild, right?

This simple patent image very clearly illustrates how the system would work.

Toyota describes it as the following in the patent application’s abstract:

“In a car wash judgement system, an acquirer acquires traveling information of a vehicle. A condition retaining unit retains a certain car wash condition. A judgement unit judges whether or not traveling information acquired at the acquirer satisfies the certain car wash condition. An unpaved road information retaining unit retains unpaved road information indicating of an unpaved road. The certain car wash condition includes traveling on an unpaved road by the vehicle. When a vehicle that has transmitted traveling information is an automated driving vehicle capable of performing automated driving  and when the traveling information of the automated driving vehicle satisfies the car wash condition, a car wash instruction unit transmits an instruction signal for moving the automated driving vehicle to a car wash station.”

In layman’s terms, if the car is going somewhere it knows is dirty, it will notify the car wash, which will in turn instruct the car to drive there and get itself clean if need be.

See: Toyota And MIT Working Toward Making Autonomous Cars More Human-Like

The following diagram details the logic of the “judgement unit”.

The system uses a set of parameters and conditional statements to determine whether or not the car needs to be washed, and will run the self-driving protocol to the car wash if it sees fit. Things like positioning information, road conditions, weather, and available time are all taken into account.

Read: Toyota To Invest $400 Millon In Self-Driving Startup Pony.ai

The whole idea begs an interesting question not often thought about: If cars become fully autonomous and are no longer privately owned, how do they get clean? And in this case, it seems Toyota has provided the answer to that question with its car wash judgement system.