Alfred: Why bats, Master Wayne?
Bruce Wayne: Bats frighten me. It's time my enemies shared my dread.
When the Tumbler leaps toward the steeply-angled rooftop (the shingled roof with dormers), beyond it is a tall office building on the opposite side of a highway that is running perpendicular to the Tumbler's direction of travel (and parallel to the face of the office building). In order to leap onto this highway, the Tumbler will need to make a hard left or right turn, as going straight will take it across the highway into the face of the office building. But as the Tumbler reaches the end of the angled roof, suddenly the office building has moved far to the left, and the highway is now nearly in line with the Tumbler's direction, running into the distance next to the office building, and passes along the left side of the shingled roof, making it easy for the Tumbler to leap easily onto the roadway.
Some people wanted the Batmobile to be computer generated, but director Christopher Nolan refused, so it was built from scratch. It can do 0-60 in 6 seconds.