Just after 4:30 a.m., Sacramento Fire Department's Engine 18 and Medic 15 crews responded to westbound Interstate 80 just west of Truxel Road for a maternity call.
When crews arrived, the baby had already been delivered with the father's assistance, according to the Sacramento Fire Department.
There were no complications during delivery and both mom and baby are healthy, according to radio reports.
No further details were immediately available.