After the NHTSA called its self-driving school bus operating in Florida "unlawful," French transport company Transdev will halt its autonomous vehicle.

The NHTSA originally gave Transdev the approval to temporarily import the EZ Generation II bus for testing and demonstration purposes, but not to transport children to school. The NHTSA said the bus is in violation of its temporary import authorization.

The company did not disclose its intentions to use the self-driving shuttle as a school bus. Such vehicles are subject to intense federal regulations that "take into account their unique purpose of transporting children," the NHTSA said. The company never received approval to use its EZ10 shuttle to transport children.

"Innovation must not come at the risk of public safety," said Heidi King, the NHTSA's deputy administrator.  "Using a non-compliant test vehicle to transport children is irresponsible, inappropriate, and in direct violation of the terms of Transdev’s approved test project."

The self-driving bus with room for 12 children was scheduled to begin transporting kids to the Babcock Ranch community in southwest Florida later this month. According to the company, the bus is designed to travel at 8 mph, but could reach speeds of 30 mph. A safety operator was to ride with the children at all times in case of any malfunctions with the self-driving system.

However, the controversy wrote itself. School buses aren't exactly an ideal platform to test unproven technology. While fatal crashes have been limited, this year's incident involving an Uber self-driving car striking and killing a pedestrian proved the technology isn't ready for prime time just yet.