The reason this episode is longer than most (68 minutes instead of the usual 60 minutes for season premiers) is because budget cuts forced two episodes to be condensed into one. Originally season two was supposed to have 14 episodes, with the first episode being titled "Miles Behind Us" and the second episode "What Lies Ahead." "Miles Behind Us" was supposed to tell the story of how the group got out of Atlanta after fleeing the CDC (these scenes are included as deleted scenes on the DVD/Blu-Ray of season two). "Miles Behind Us" was also going to include a flashback scene showing the backstory of the Army Ranger played by Sam Witwer that was in the tank and was shot by Rick after he had turned, came to be in the predicament that forced him to take shelter inside the tank and die.
An average car is too low to the ground for a person to squeeze under. So the production used "soccer mom cars and redneck trucks" instead.
The scene where the group is hiding under the cars was shot in Georgia on Highway 20 during a heat wave.
In front of the church that plays a prominent role in What Lies Ahead (2011) (#2.1), the bible verse Revelation 16:17 is referenced on a sign. That is a bible verse that describes the wrath of God during the apocalypse.
The episode won an Emmy Award for Outstanding Prosthetic Makeup for a Series, Miniseries, Movie or a Special.