I didn't take it that way, Dave.
My wife was driving and I was shooting.
No, street photography is documentary photography -- documenting people and their activities -- which, among other things, doesn't tell a complete story. "Ambiguous" is the word people use to differentiate street from normal documentary, photojournalism for instance, but "ambiguous" doesn't really describe the difference. To understand the difference you need to study the work of people like Henri Cartier-Bresson who didn't invent it, but who defined it with his surrealistic early photographs. Other street masters worth studying are Andre Kertesz, Robert Doisneau, Willy Ronis, Walker Evans, Elliott Erwitt, Marc Riboud, Helen Levitt, Robert Frank, Garry Winogrand, and Lee Friedlander to name just a few. Some of these people were photojournalists, and you have to distinguish between the documentary photography they did on the job and the street photography they did in their spare time.
Last year I wrote a couple short articles on the subject. Having spent years submitting poetry to "little magazines," with a fair amount of acceptance but with too much work, I never got serious about sending out the articles. I enjoyed writing them, but I don't really care that I can't read them in a magazine. They're at:http://www.russ-lewis.com/essays/OnStreetPhotography.html
But FedEx isn't street photography. It's highway photography, or, as Slobodan points out, actually landscape. That's fun too.