Investing.com -- The head of the U.S. National Highway Traffic Safety Administration on Wednesday told self-driving car companies they must quickly fix a "clear pattern" of driverless vehicles interfering with law enforcement and other first responders.

Jonathan Morrison, who leads the U.S. vehicle regulatory agency, wrote to the industry that NHTSA has documented multiple instances of autonomous vehicles driving "directly into active emergency scenes, blocked the paths of ambulances and firefighters, or failed to recognize and respond to basic safety conditions like flashing lights, flares, smoke, fire, and traffic cones."

NHTSA said the situation was unacceptable and stated it would schedule meetings with vehicle developers by the end of this month to hear their solutions.