Coming into Port Isabel from South Padre Island the speed limit signs are 65 mph. I found it interesting that the speed limit signs dropped to 45 mph outside the city, then to 30 mph, but the speed limit on my GPS unit stayed at 65 mph. The GPS finally dropped just outside the city. I have never had a problem with my GPS speed display. It normally changes within a second of passing a speed limit sign, but not in Port Isabel. This happened to be around spring break and I noticed 3 police vehicles pulling over speeders in heavy traffic on both sides of the highway. (so going into and coming out of Port Isabel) I wonder if they moved their signs to reduce speed further out of the city during heavy traffic times? I see both a safety responsibility because of increased pedestrian traffic, but also a business opportunity with increase ticket revenue for the city. Call it what you want, it’s still a speed trap. I think a couple of signs warning drivers to “reduce speed ahead, heavy pedestrian traffic” would work better from a safty point of view. Too many people rely on their GPS units to verify speed limits, especially in heavy traffic when you are watching cars and changing lanes to give the pulled over vehicles more room.