Because our govt is a bunch of paranoid retards. Its not the guys n the field who are at fault. Thats a pain in the ass Jeff. Its a shame they are wasting your guys time with bullshit. The only way to secure a bridge is to STOP CARS going over it. Dont you think of some insain religious retard wanted to blow up a bridge they would do the same thing they are used to doing all over and world? Which is fill a vehical with things that go boom then make them go boom where they wanted to?