"PCH" stands for Pacific Coast Highway. (Yes, it also stands for Publisher's Clearing House, but that has nothing to do with this song.) The song is about pleasure riding a motorcycle on the Pacific Coast Highway.
Key points that support this:
"I was out on the coastline/Getting a little shake"—the shake of a motorcycle, that is
"Eatin' up asphalt"—on the road, traveling many miles
"Want to head north/But I might go south"—the PCH runs north and south along the coast
"PCH" stands for Pacific Coast Highway. (Yes, it also stands for Publisher's Clearing House, but that has nothing to do with this song.) The song is about pleasure riding a motorcycle on the Pacific Coast Highway.
Key points that support this: