June 25, 2011: Spray Paint Hieroglyphics

Every profession has it's language, its codes, its symbols that the means of interpretation are held only by those that practice that profession.  As I walk the streets of Pella, IA, that code is expressed by spray paint on the sidewalks by the street department that relates to construction activities that are going on.  I presume the blue near the top of the photo represents water since it is near a drain? The orange providing instructions regarding curbside gutters?  But what does the orange T represent that differs from the straight lines?  And why the asymmetry? I also saw yellow arrows running down sidewalks.  Probably everyone from the city public works director on down in that department knows what all of this means, but I walk in ignorance, as do most of us.  Somewhere is a plan, a map, and someone has to put the marks on the grounds that are a recipe for construction.  Instructions as to what is to happen where, in a common code that all involved know what to do.  I wonder if this code is common only to the city of Pella, or if people all over the state, country, or even the world use it.  I wonder if the code traces it's roots to the ancient Romans, or beyond.