Robotaxi companies refuse to say how often their AVs require remote support.

In February, Sen. Ed Markey (D-MA) sent a letter with a list of questions to seven U.S. companies working on self-driving car technology. He specifically wanted to know how much these companies’ vehicles, run by Aurora, May Mobility, Motional, Nuro, Tesla, Waymo, and Zoox, relied on input from remote staff. They all declined to speak, according to Markey’s findings released Tuesday.

The information released by Markey’s office is the latest example of the reluctance of self-driving car companies to share details about how their operations actually work, even as they all experiment with the technology on public roads.

“This report reveals an alarming lack of transparency regarding the use of AV companies. [remote assistance operators] Help guide your AV. “This investigation revealed a patchwork of safety practices across the industry, with wide variations in operator qualifications, response times, and international staffing, with no federal standards governing these operations,” Markey’s office said in the report.

Markey said Tuesday that he is asking the National Highway Traffic Safety Administration to investigate the use of remote operators by these companies and is “working on legislation to impose strict guardrails on the use of remote operators by AV companies.”

TechCrunch reached out to each of the companies named. Waymo and Nuro declined to comment. Aurora and May Mobility said they appreciate the collaboration with Mr. Markey’s office. The others did not respond to requests for comment.

Markey launched his investigation in February after a Senate Commerce Committee hearing on the future of self-driving cars. During the hearing, Waymo Chief Safety Officer Mauricio Peña said that when the company’s vehicles find themselves in difficult or unexpected scenarios, guidance from “remote assistance” staff may be needed. Peña also revealed that about half of Waymo’s remote support staff are based in the Philippines.

Self-driving car companies have talked about this type of remote assistance operation many times over the years. But those conversations were often theoretical, as the technology was still in the speculative or testing stages.

Now that many of these companies have commercially introduced robotaxis, or, in Aurora’s case, self-driving semi-trucks, their entire operations are receiving increased attention.

After the hearing, Mr. Markey sent letters to these seven companies requesting further information regarding remote control. His office asked each company 14 questions, including how often remote staff instruct self-driving cars, the size of their teams, their locations, how they obtain licenses, and the types of security protocols they have in place.

Companies’ responses (you can read the full text here) vary widely. Waymo and May Mobility specifically claim that this is “business-sensitive information,” and no one directly answered questions about how often remote staff provide guidance to AVs. Tesla didn’t even include this question in its response. For reasons that aren’t clear, the company eliminated its North American communications team several years ago.

Waymo claimed in the letter that improvements to its self-driving system have “significantly reduced” the number of requests for help per mile that its vehicles send to remote staff, without providing specifics or evidence. The company wrote that the “vast majority of requests” that the robotaxis send to remote assistance staff will be resolved by the self-driving system “before an agent can respond.”

Waymo is also the only company allowed to hire remote support personnel from overseas. While the company says it is making sure these workers have local driver’s licenses, Markey’s office wrote on Tuesday that “a foreign driver’s license is not a substitute for passing a U.S. driver’s license test, as traffic rules almost certainly vary from location to location.”

All companies except Tesla claimed that they do not allow or have the ability to allow remote assistance staff to directly control these self-driving cars. Meanwhile, Tesla said its remote support staff have been “authorized to temporarily assume direct control of the vehicle as a final escalation operation after all other available interventions have been exhausted.”

Tesla said this could only happen if the pilot vehicle’s vehicles were traveling at speeds of 2 miles per hour or less, and remote operators could not drive the vehicles at speeds greater than 16 miles per hour.

“This feature allows Tesla to quickly move vehicles that may be in a dangerous position, thereby reducing the need to wait for first responders or Tesla field personnel to manually retrieve the vehicle,” the company said in a letter to Markey’s office.

This has been a source of criticism for Waymo recently. Waymo faced tough questions from San Francisco city officials during a public hearing this month about its reliance on first responders to move stranded robotaxis. As TechCrunch recently detailed, Waymo has a dedicated “roadside assistance” team separate from its remote assistance staff. But this part of Waymo’s operations was not the focus of Markey’s investigation.

Mr. Markey’s office stole some other information from these companies. His report shows the delays associated with these remote assistance interactions (varies from company to company, but May Mobility reports a maximum worst-case figure of 500 milliseconds), how some companies keep these employees fatigued, and what precautions they take to protect the data they monitor.

These are questions that self-driving car companies have faced for years, and the answers haven’t been easy to find. But with more commercial developments on the horizon, Markey’s office will definitely not be the last to ask or request further details.

This article has been updated to reflect the companies’ responses.