Since completion of the freeway, the route has not been changed.
With the completion of this freeway, Route 24 east of the John F. Kennedy Parkway became Route 124.
Following the completion of the freeway, PA 63 was extended east onto it.
With the completion of the freeway, a portion of the former route was briefly known as Route 21A.
Upon completion of the freeway in 1968, the new highway was designated I-378, a spur off of I-78.
Though the National Freeway was designated as US 48, as the completion of the freeway neared, the possibility of the freeway being designated as an Interstate highway came up.
Following the completion of the freeway, the former signed route of Route 24 between the junction with U.S. Route 202 in Morristown and the John F. Kennedy Parkway became a western extension of Route 124.
That year, many gas station, motel, and restaurant owners noticed a drop in business, possibly due to concerns regarding construction traffic due to I-8; however, they hoped for increased business following completion of the freeway.
As the scheduled completion of the freeway neared, Mayor Tom Hamilton of Chula Vista expressed concerns regarding the predicted development of the I-805 corridor, and the decisions that the City Council would need to make regarding such plans.
But in 1960, Jacob Dekema, the district highway engineer, stated that due to lower traffic on US 80, the completion of the freeway through the mountains would be delayed until at least 1971.
