Rep. Raja Krishnamoorthi has asked the Department of Transportation to explain its oversight of Tesla's Autopilot and Full Self-Driving systems. The request follows an NBC News investigation that surfaced 43 videos of drivers appearing to be asleep while using the features.

The congressman's letter demands the DOT clarify what actions it is taking regarding these systems. The videos raise concerns about driver engagement and the safety of Tesla's driver-assist technology.

This is a developing story. The DOT has not yet publicly responded to the congressman's request.