Jimmy Webb's "Highwayman" is based on a dream that the songwriter had after "some professional drinking" with Harry Nilsson.

 

I was in London, finishing an album, El Mirage, with George Martin. My friend Harry Nilsson was there, and we were doing some professional drinking. He left my apartment one night, and I went to sleep and had an incredibly vivid dream. I had an old brace of pistols in my belt and I was riding, hell-bent for leather, down these country roads, with sweat pouring off of my body. I was terrified because I was being pursued by police, who were on the verge of shooting me. It was very real. I sat up in bed, sweating through my pajamas. Without even thinking about it, I stumbled out of bed to the piano and started playing “Highwayman.” Within a couple of hours, I had the first verse.
Nilsson hated that line, “Along the coach roads I did ride.” He said, “You mean, ‘Along the coach roads you rode?’” In that particular case, I felt it was justified because it was kind of an antique way of speaking.

-- Jimmy Webb [1]