According to this rather official- and thorough-looking discography, Ewan MacColl did indeed write a song called THE DRIVER'S SONG and it begins "Come all you gallant drivers, wherever you may be" © 1963 (although it also bears the date 1958)

Lyrics have been posted here: Lyr Add: DRIVER'S SONG (Ewan MacColl)

Although the word "bulldozer" doesn't appear in it, it is clearly about digging and road-building, and it mentions a "Cat"—short for Caterpillar, a brand of bulldozer.

I was curious about the origin of the term "bulldozer" so I looked it up in Wikipedia and found this:

* Around 1880: In the USA, a "bull-dose" was a large and efficient dose of any sort of medicine or punishment. 'Bull-dosing' meant a severe whipping or coercion, or other intimidation such as at gunpoint.

* Late 19th century: "bulldozing" meant using big force to push over or through any obstacle.

* 1930s: applied to the vehicle.