It takes millions of giant green placards to make America navigable. Where do they come from — and who pays the bill? Zachary Crockett takes the exit. 

• SOURCES:
  • Lee Blackman, general manager at Correction Enterprises.
  • Gene Hawkins, senior principal engineer at Kittelson and professor emeritus of civil engineering at Texas A&M University.
  • Renee Roach, state signing and delineation engineer for the North Carolina Department of Transportation.

• RESOURCES:
  • "Manual on Uniform Traffic Control Devices for Streets and Highways, 11th Edition," by the U.S. Department of Transportation Federal Highway Administration (2023).
  • "Who Picks the Businesses on Highway Exit Signs?" by Janet Nguyen (Marketplace, 2022).
  • "The Road to Clarity," by Joshua Yaffa (The New York Times Magazine, 2007).

• EXTRAS:
  • "Do People Pay Attention to Signs?" by No Stupid Questions (2022).