The Hitchhiking Ghost

I saw a ghost in broad daylight.
Mike and I were on our way to Grasslands National Park in Saskatchewan and decided to check out Highway 41 as we’d never been on it. It was a clear, blue sunshiny day in June with the near-endless visibility you get out on the prairies. A beautiful day for a drive and not much traffic on the road.
It was right around 2 p.m. We were minding our own business heading south with Mike behind the wheel. The road just ahead dipped a bit, then went up a slight hill with a curve. I don’t know if there was a stream in the dip or not, but there were guardrails.
I saw young man, maybe 20-30 years old, standing on the right-hand shoulder. I think he had a small suitcase beside him. He walked over to the centre line, picked something up off the pavement, and then walked back to the shoulder.
Okay, I thought, we’ve got a hitchhiker ahead. I turned to Mike and told him to watch out for the guy in case he tried to go to the centre line again.
But when I turned back the road was empty. A three or four ton truck came down the hill and sped by us on its way north.
No other traffic. No one had stopped to collect this young fellow. He was just gone.
Mike didn’t say anything. I was at a loss, too.
A ghost in broad daylight. Wonderful.
I haven’t had a chance to take that highway again, but I want to. What’s this guy’s story? Is he waiting for a ride that never showed? Was he killed by a vehicle while retrieving something from the middle of the road?
I’m not just curious. I’d like to help the poor fellow. Haven’t got the first clue how to help a ghost, but I’d like to at least talk to him.