Tesla has confirmed that its robotaxis are occasionally operated by remote human drivers, according to the company's response to questions from a U.S. senator investigating autonomous vehicle transparency.

The electric vehicle manufacturer stated that remote human intervention occurs rarely and only at speeds below 10 miles per hour. The disclosure came as part of Senator Ed Markey's recent investigation into how frequently autonomous vehicles require human assistance during operations.

Multiple major autonomous vehicle companies, including Aurora, May Mobility, Motional, Nuro, Tesla, Waymo, and Zoox, declined to provide specific data on how often their vehicles need remote human intervention when contacted by Markey's office. The lack of disclosure has prompted calls for greater transparency in the autonomous vehicle industry.

The revelations come amid broader scrutiny of driver assistance and autonomous vehicle technologies. The National Transportation Safety Board recently investigated two fatal crashes involving Ford's BlueCruise hands-free driving system, which resulted in three deaths. The NTSB determined that drivers in those incidents relied too heavily on the automated technology.

The autonomous vehicle industry has faced increasing regulatory attention as companies expand testing and deployment of self-driving technologies. Safety advocates have long called for more detailed reporting requirements regarding when and how often human operators must intervene in autonomous vehicle operations.