Fans of the Macy's Thanksgiving Day Parade who come to see the soaring SpongeBob and Snoopy balloons may get a far less heartwarming sight this year: giant dump trucks filled with sand. More than 80 city sanitation trucks will be used at intersections and other strategic spots along the 2 ½ mile parade route to create an imposing physical barrier to terror. The trucks weigh about 16 tons empty and up to twice that with sand.