Did you know that interstates are numbered based on a systematic grid? Odd-numbered routes run north-south with lower numbers in the west, while even-numbered routes run east-west with lower numbers in the south. Major routes that span the country typically end in a “0” or “5” (e.g., I-10 and I-95) and auxiliary routes have three-digit numbers that indicate their connection to a primary interstate.
This video is bonkers and fascinating all at once!