The page holds an iframe with the map inside of it. That iframe is constantly being updated and redrawn. The real beauty is the fact that you can drag the map around and follow a road. The directions functionality leaves something to be desired (much like MapQuest). I entered my address in Houston and tried to get directions to Lubbock and it gave me a route through DFW which is about 3 hrs. out of the way. I am guessing that it tries to stick to the major highways when giving directions but I really wish there was an option to get quicker directions.
The last thing I noticed was the fact that the maps are a little outdated. There are some streets and landmarks in Lubbock that are missing or are no longer here. Once they get that done then they will have an unstoppable service…. Can you say “Goodbye MapQuest”?