The answer, apparently, is seven. There's one behind the truck (you can just make out his feet by the rear tire) and another in the cab. Tax dollars at work. I don't think this is the kind of "putting people to work" Obama had in mind.

I took this today on my way to a client meeting. It must have been stoplight maintenance day, because these trucks where everywhere.

(Not a bad photo, if I may say, for having been shot through the windshield.)