I'm working on putting together an RFP for a consultant to assist our department with the creation of a set of architectural guidelines for the municipality. It will have sections targeted toward historic districts, buffer neighborhoods (basically, conservation districts), and commercial districts and will address both building and site design. Several of our commercial districts contain a lot of auto-oriented businesses - by "auto oriented" I mean set back from the street, with parking in front and high-visibility signage designed for motorists. The older commercial districts here tend to be built to a more human scale, with parking behind the structures and facades located directly at the sidewalk's edge.
The latter type of commercial district is easier to write guidelines for than the former, as there are fewer corporate prototypes (like a Sunoco gas station or a Burger King) and more 19th century historic structures with real architectural detailing. Has anyone had any experience with creating guidelines for auto-oriented "sprawl" style business districts? Right now, I'm thinking that the best we can do is kind of work around the edges for these areas as the chance of a wholesale change in character is nonexistent.