to get across the second bridge you got to put in the flying car cheat it is right,R2,O,R1,L2,down,L1,R1 and the better driving skills and that one is R1,L1,R2,L1,left,R1,R1,triangle then go as fast as you can and hit L3 that is the left control stick push down on it while you are at the end of the bridge while driving and it will send you flying across the bridge if you do not make it the first few times keep trying you will get it i now the for a fact.

you don't go over the bridge. you find the tunnels that you drive throughout to get to francis national air port or shoreside vale. i dont know exactly where this tunnel is, but ill try to find it and tell you.

ok...
on staunton island there is a big stadium. go to the northwest corner on the outside of the stadium. you will see 2 "rockstar games" signs. go doun the road thant they are facing. one of those right turns is a big tunnel. follow the blue overhead signs straight on to shoreside vale.

I've looked at some of these anwsers and they're not very good. enter the dodo cheat (R2,O,R1,L2,down,L1,R1 ) i think thats it) and enter the tank cheat ( find that urself, its not hard) . While driving the tank point the barrel of the tank behind you, and shoot it to get up speed. So get up speed, and with the dodo cheat compined with the speed you get by shooting the tank backwards you shud get over the gap. Or you cud just get off ur ass and do sum missions.

First put in the fly cheat....... right, R2,O,R1,L2,down,L1,R1 and improved car handeling R1,L1,R2,L1,left,R1x2,triangle. Press L3 to make car jump

Then get one of the really fast cars like a Banshee or an Infernus,
drive up the bride and follow the grey part that separates the 2 driving lanes,
drive up it as the front is like a ramp,then,
drive forward (but dont go really fast because it causes the car to spin and jump off the grey part)
holding L3upwards the fly off the end and pull L3 downwards like your flying a plane for a steady take off ) VOILA!!

U DONT , YOU TAKE THE SUBWAY

At the start of the broken bridge in portland there should be a few signs blocking the entrance of the bridge. steal or spawn a fast car then put the dodo and the good handling cheats in and face forward to the signs. Quickly reverse backward until you think your far enough then stop and speed straight forward towards the bridge. If so the car may fly but if this does not work tap L3 and you will jump over the signs.when you're over don't stop driving and when you come to the broken hoole Quickly tapL3 or just let the car fly over the crack. Hope this cheat works for you..
(:C^H,.E,/A#T~M{A}S#T,.E=R!!!!!!!!!