EXIT Sign Coloration:
An Analysis of Geographical Distribution

Brent Emerson

My name is (first) (last). My email address is .
I live in (city), (state), where the exit signs are .

Everyone knows that STOP signs are red. From Alaska to Florida, traffic lights are the same: red means stop and green means go. Interstate highway signs are green--orange means watch out for construction, yellow means watch out for something else. All across the country, people know these things. We learn them in elementary school, in driver's education classes, in experiencing the world around us.

I grew up in Salt Lake City, Utah, where I learned that illuminated EXIT signs are green. Makes sense: green means go, you go to exits... Imagine my shock when I went to school in the East and was thrust into a strange world of red EXIT signs. The first time I noticed, I just figured that all EXIT signs were red--I was just misremembering my childhood. Further observation revealed that I was wrong--every single EXIT sign I could find in the public buildings of Salt Lake City was green, while every single EXIT sign I'd encountered in the East was red. This seemed odd. Now Salt Lake City is certainly an odd place, but this didn't turn out to be about Salt Lake--every time I've traveled anywhere in the country, I look for EXIT signs, and they seem to follow a simple pattern: signs in the West are green, signs in the East are red.

Well, a simple and totally unexpected trend like this deserves further attention: is there really a simple split? Where is the dividing line between EXIT sign east and EXIT sign west? This page is my stab at a reasonably rigorous analysis. It records two years of electronic communication between me and people all over the country.

This project is now closed.

The current map is the 7th produced, reflecting data gathered before August 1999. This map has not been updated to reflect the hundreds of data points submitted since that time. From the beginning of this project on 16 February 1998 until 17 January 2001, over 500 contributors submitted data points, only a few of which are shown on the map. Many people have contributed additional comments, some of which are reproduced here.

Thanks to USA Today, for sending most of them this way.