Authorities say a woman in labor didn't make it to the hospital and gave birth in a vehicle on the shoulder of Interstate 270 during rush hour.
Maryland State Police and Montgomery County fire and rescue crews were called to southbound I-270 near Route 118 in the Germantown area around 6:30 a.m. Thursday.
Assistant Chief Scott Graham, a spokesman for the fire department, says the baby girl was born before crews arrived. He says the mother, baby and father are all doing well.
Police say the mother and baby were taken to Shady Grove Adventist Hospital in Rockville.
The unusual birth comes just a few weeks after a baby was born on a platform at the L'Enfant Plaza Metro station.