Sarah Kam, 33, set out for the hospital with her husband, Hugh, after she went into labour at their home in Omaha, Nebraska.
As the couple drove along Interstate 80, however, Sarah realised that they were too late - their baby daughter was on her way and there was no turning back.
"Oh, no, it's happening again!" Sarah cried. For, astonishingly, this was not the first time the couple had experienced a roadside birth.
Their first child, three-year-old Ethan, had a normal hospital birth. But in February last year, Hugh and Sarah were making the same dash to the birth centre when Ethan's little brother Ezra beat them to it, arriving en route only minutes away from their destination.
This time, the couple were once again pipped to the finish line by the new arrival, baby daughter Evelyn.
"You've got to catch her, or she's going to go on the floor," Sarah recalls telling her husband, who stopped the car just in time to catch the newborn.
Even more spookily, Hugh realised he had pulled over into the exact same hard shoulder where he had screeched to a halt during Ezra's birth.
After managing to get through their second front-seat labour, Hugh and Sarah headed off to the birth centre as planned - but with their new baby already in tow.
Once there, mother and baby were examined by midwives, and are now both at home and doing well.
Sarah told Omaha.com that the hard shoulder had become a strange part of their family's story: "When they're bigger, we'll have to go there and take a picture of them."
Hugh admitted that, while he was 'kind of nervous' when he realised his wife was about to give birth in the car, after last time it was not entirely unexpected - he had even taken the precaution of covering his Lexus' leather seats!