The produce grown in the gardens at the Kingdom set doesn't go to waste. Anything that isn't used is donated to local food drives and churches.
The most memorable part of the highway sequence for Alanna Masterson was repeatedly pushing a car up hill with Chandler Riggs. She joked "My glutes will never be the same."
Greg Nicotero's (director of this episode) kids are shooting arrows in the background when King Ezekiel (Khary Payton) is talking to the group.
It wasn't the first time the stretch of the highway has had an apocalyptic road block. It was also featured in episode 2.1, The Walking Dead: What Lies Ahead (2011), when the group came up on a pile up with a Walker horde and where Sophia (Madison Lintz) went missing. It only took 2 days to shoot. The sequence where the group is unwrapping all the explosives and the huge explosion were filmed on August 23, 2016 & The entire Walker sequence and moving the cars where filmed on August 24, 2016.