The invention contemplates a copolymer which is a graft or block copolymer useful to change wettability and surface characteristics of biological surfaces. The first section has a first end surface configured for positioning against the first bone. The surveillance may begin immediately upon receipt of the trigger signal from an emergency vehicle, or may wait until the intersection controller determines that the signaling emergency vehicle is in the field of view of the cameras at the intersection. Therefore, the dielectric layer on the protrusion is thinner. Then computing the size of the object according to the proportion and the actual size of the captured area, and displaying the measured size of the object.