Lone Candle

“An obscure federal rule is slowing the self-driving revolution. When trucks break down, operators are required to place reflective warning cones and road flares around the truck to warn other motorists. The regulations are exacting: Within 10 minutes of stopping, three warning signals must be set in specific locations around the truck.
Aurora asked the federal Department of Transportation (DOT) to allow warning beacons to be fixed to the truck itself—and activated when a truck becomes disabled. The warning beacons would face both forward and backward, would be more visible
than cones (particularly at night), and wouldn’t burn out like road flares. Drivers of nonautonomous vehicles could also benefit from that rule change, as they would no longer have to walk into traffic to place the required safety signals.

In December 2024, however, the DOT denied Aurora’s request for an exemption to the existing rules, even though regulators admitted in the Federal Register that no evidence indicated the truck-mounted beacons would be less safe. Such a study is now underway, but it’s unclear how long it will take to draw any conclusions.”

https://reason.com/2025/10/19/feds-pump-the-brakes-on-autonomous-trucks/