A friend from Bristol (UK) used to sing us this cummulative children's song, which involved a trolly bus and several other tongue-twistings additions. Can't find it in my search of the DT archieves. Can anyone help?

POOR OLD MAN CROSSING THE ROAD

A poor old man was crossing the road,
Crossing the road, crossing the road;
A poor old man was crossing the road
When along came a...?
Which ran over the poor old man.