Here is MY theory that I didn't want to put in the film. Theories are always seemingly picked out before the evidence that cause the theory in the first place.
The Five poles are removed at night through a phony late night road construction detail the week(s) or months prior to 9/11.
Then EARLY on the morning of 9/11 laid out poles 2-5 in the grass. Everyone drives by not noticing 4 poles laid out, inconspicuously, in the grass.
Then shortly before the entrance of our mystery flyover plane...
Perps drive large truck with pole and/or with cab on trailer(cab can also be on another car perhaps car 2 in the southbound lane) northbound throw crushed up glass out by the off ramp by pole 3, and go under bridge drive up on the south bound loop. (Variant: or there are two teams in cars that throw out glass and/or bulb housing debris. One car on northbound loop exit and one southbound lanes near pole 1 and eventual resting spot of the cab.)
Right after the plane flies over and explosion goes off...
Police(blue) get diverted from gas station, the truck/trailer perps stop on loop as if they are shocked. Taxi is unloaded off trailer(yellow) while all are staring at the Pentagon. Truck continues up on the on ramp drops pole 1(green) in the fast/middle southbound lane street on bridge and perhaps bulb/glass debris. Cab eases his way up on the highway with "damage". Our police officer was adamant when he said he was sure the cab was over near that overhead sign (the one the plane flew over), near the on ramp...not on the bridge.
As everyone is distracted, the cabbie pulls up to the final point, the faceless guys in the Saturn pull up and move the pole making the scratch in the asphalt, so they can park their car. And with the assistance of the faceless shirt and tie men in the fire dept Saturn he turns his cab sideways near the pole, giving the appearance that he is helping block traffic going soutbound. Then, perhaps the shirt and tie guys (instead the variant -car 2 sthbound lane) in the Saturn stand around and maybe even drop the glass, bulb pieces perhaps even the little pieces of leaves.
These two easily rival Eric Cartman, though. I understand Merc even has the volatile anger thing down.
