"The pole missed striking the vehicle driver by mere inches," the Prince George's County Fire/EMS Department said in a statement. "The pole pierced his roof, went through the interior and came out the bottom of the car."
The driver walked away from the episode unharmed, officials said.
The pole had been knocked over during a car crash that unfolded in front of the driver, officials said.
An ambulance had hit the pole after being sideswiped by a civilian vehicle, different from the one damaged by the pole, on the Capital Beltway, officials said.
Officers from the Prince George's County Police Department were interviewing the driver of the vehicle that struck the ambulance, officials said, and information about any possible charges was not immediately available.
Two medics in the ambulance sustained non-life-threatening injuries and were evaluated at a trauma center, where they were listed in good condition, according to officials.