The responses to NHTSA's questions so far are redacted entirely, citing "confidential business information."

The security review is being performed by the Idaho National Laboratory, and the research is being funded by a company -- or a group of companies -- in the electric and autonomous vehicle industries.

Tesla and eight other automakers will install warning labels that help occupants identify the often hard-to-find manual door releases.

Together, these permits would allow up to 8,000 robotaxis to be deployed over the next 12 months.