To designate where a pilot and their aircraft are at an airport, there are these signs near each intersection. I took this shot during the media flight of Hawaiian Air's Bellanca Pacemaker. The photo above shows us at the intersection of Taxiway F and Runway 4R/22L. The control tower instructed our pilot to hold short of Runway 4R. The workers in the background are from the US Air Force. They are doing maintenance on the barrier cable that runs across Runway 4R for fighter planes in distress.