So are you saying the additional 12 meters (about 39 feet) does not mean that much?
I am assuming this is because the GPS knows that I'm not driving on my neighbors' lawns and must be on the street, so it puts me on the street. Do all auto GPS systems like the Garmin do this?
I tend to agree that, it is doubtful that WAAS enhances the use of GPS for automotive purposes but it does not degrade it either.
Something else about WAAS that is worth mentioning... The GPS satellites are supposed to travel in their designated orbits. Sometimes they can be a little "off" from where they are supposed to be. The WAAS system calculates how much they are off, and provides correction information to your GPS.So if all of the satellites were exactly where they are supposed to be, no correction information would need to be applied. Therefore your position wouldn't be any different, WAAS or no WAAS. Of course that doesn't happen and correction information does help, but depending on how far "out" things are, the satellites you are connected to, etc the benefit won't always be significant.