The 12-person shuttle is fully electric, and for the time being, it was limited to just 8 mph.

That said, adding "necessary infrastructure" could have boosted that speed to 30 mph in due time.    

But it's not gonna happen, not as a school bus at least.

The National Highway Traffic Safety Administration has sent a letter to Transdev, requesting that it stop using its EZ10 Generation II autonomous shuttle as a school bus.     

The 12-person shuttle is (or, rather, was) used to take children to and from Babcock Neighborhood School in Babcock Ranch, Florida.    

In a press release, NHTSA claims that Transdev was given permission to "temporarily" import its driverless shuttle for "testing and demonstration purposes," and that the company never received the green light from the feds to use it as a school bus.    

If Transdev doesn't take heed immediately, NHTSA said it could result in a "civil penalty action."

NHTSA could also deport the shuttle if Transdev doesn't get its act together.

Transdev did not immediately return a request for comment, but NHTSA said Transdev signaled that it would cease the unlawful activity.