My object was to stop him getting as far as the corner.

He must have been thinking too hard to be aware of his surroundings.

I put myself in his way, and he nearly walked into me.
"Hallo!" I said.
His surprise was extreme.

"You here! You don't mean to say you have been waiting for me ?" I said negligently that I had been detained by unexpected business in the neighbourhood, and thus happened to catch sight of him coming out.
He stared at me with solemn distraction, obviously thinking of something else.

I suggested that he had better take the next city-ward tramcar.