Pulling over, the group discovered a 1-month-old baby in a car seat stuffed with $5,500 USD ($6977 AUD) and a social security card.
According to Fox News, the little boy is now in state custody and authorities are investigating why the baby was abandoned.
The little boy was likely left outside for about 30 minutes in 32-degree heat.
The child’s mother has since been located by authorities, and she has been sent to a hospital for evaluation, the New York Daily News reports.
"We don't know why she did what she did ... but people do the strangest things sometimes," Sgt. Gary Knight explained. "I don't recall seeing a case like this where a baby was just left on the shoulder of a highway. This could have had a very tragic ending."
This article originally appeared on marie claire.