Well, Exrald, I figure you were blasting out of Walnut Creek and merging onto 24, heading west. So, I reckon you could consider that an on ramp .....
Now about that sound you heard, I have a theory ........ comes from back-in-the-day, when I lived in Danville and rushed to work in Richmond.
"Now the boys all thought I'd lost my sense
And telephone poles looked like a picket fence.
They said, "Slow down! I see spots!
The lines on the road just look like dots."
Took a corner; sideswiped a truck,
Crossed my fingers just for luck.
My fenders was clickin' the guardrail posts.
The guy beside me was white as a ghost."
So, just don't hit the guardrail posts .....
humfrz