Lets say I have a character, and all around them is difficult terrain for 100 feet in all directions. My character have an overland movement speed of 30. From one direction double moving at 20 for a total of 40 is a creature coming to kill you, and the creature is close. Ignore how the creature is moving, its coming at you and is moving faster than you can double move, so it will catch you and kill you.
Acrobatics allows you to make horizontal jumps. Since most characters are unable to jump vast distances like monks, they will be limited to 5-15 feet jumps. Since jumps count against your movement only for the distance traveled and not the type of terrain you jump over, each square you jump is beneficial. However falling prone can be fatal. Are you allowed to make repeated 5 foot jumps for easy 5 DC checks? You could then double move the whole way by making small jumps and safely out distance the creature coming to kill you.