Seing as the bridge is on an angle and it is higher than the ground, you could try getting a care package on a slant and doing the knife lunge glitch with an M.O.A.B. This seems to work on a lot of maps...
well the only way i can see that you can do this is by using my custom patch/mod menu for xbox which allows your character to become a mesh which means you can go through barriers and walls
btw im releasing the patch in about 2 weeks