The Dark Knight Trilogy: 10 Moments That Make No Damn Sense
3. The Bit With The Gotham Blockade
Gotham under Banes rule is a weird place, the poor overthrow the rich, lawlessness runs rampant, cats marry dogs... And police officers move across the city at the speed of light easily, without anyone blinking twice in their direction.
The city is deserted, we know this because it is established quite a few times - and there aren't any cars around, because they've all been used to blockade all of the tunnels (apart from the super secret magic one that Batman must have used - more of which soon) and normal Gothamites have been forced to hide.
The only people regularly outside are Bane's army, who patrol and guard the blockaded exits out of the city, since there are presumably thousands of people in the city limits who might take any opportunity to try and escape through unguarded tunnels, whether they had cars in front of them or not. For instance through the still giant holes above the pile of cars (see above.)
After all, to entirely misquote Jurassic Park: life always finds a way.
But Bane seems to have forgotten about that bit for a while, since when Catwoman creates a way out of Gotham for the citizens, the street she heads to is empty, and the barricade is noticable without any guards whatsoever, allowing her to blow a way out quite easily. Which presumably anyone with the necessary equipment could do, without combat training or the stealth skills of a master thief...