# Road Sign Math

> A road trip game: find a road sign whose numbers make a true equation, photograph it, write the math, and post it to the map. 16 signs from 3 players in 6 states, found from 2021 to 2025.

A way is accepted when the math is true and every number in it is one of the numbers on the sign, each used no more often than the sign shows it. Using every number is encouraged, not required. Anyone can find another way on any sign. There are no points, scores or rankings.

Jamie Thingelstad started the game in 2005 as roadsignmath.com, with signs sent in by other players until 2014. This site and the iPhone app are its new era; the first era’s signs are kept in the archive on Things I’ve built, not here.

Each sign has a page at `/signs/<slug>` and each player at `/players/<handle>`. Most places are approximate: the pin sits on the town the post or the sign names. `found_on` is the day in the finder’s own time; other times are UTC.

## Data

- [Every sign](https://roadsignmath.xyz/signs.json): every shown sign, newest posted first, with its numbers, every way to make it true (as text and LaTeX), the place and coordinates, the finders, the dates and both photo sizes; open to any origin
- [Players](https://roadsignmath.xyz/players.json): everyone with a sign or a badge on the map, with their counts, states, signs and badges
- [Signs on a map](https://roadsignmath.xyz/signs.geojson): a GeoJSON FeatureCollection with a point for every sign that has a place
- [Feeds and data](https://roadsignmath.xyz/data): how to use the feeds, the files and the API, with every field documented

## Feeds

- [Atom feed](https://roadsignmath.xyz/feed.xml): the newest 50 signs; every player has their own at `/players/<handle>/feed.xml`
- [JSON Feed](https://roadsignmath.xyz/feed.json): the same signs as JSON Feed 1.1; every player has their own at `/players/<handle>/feed.json`

## API

- [API](https://roadsignmath.xyz/api/v1): public JSON reads under `/api/v1` (signs, a sign and its ways, signs near a point, the map, players, badges); posting is for the iPhone app
- [OpenAPI description](https://roadsignmath.xyz/api/v1/openapi.json): every route, parameter and field (OpenAPI 3.1)

## Pages

- [Home](https://roadsignmath.xyz/): the map of every sign with a year filter, who’s playing, the latest signs, how to play and the app
- [About](https://roadsignmath.xyz/about): the game’s story, from 2005 to the app, in Jamie’s words
- [Feeds and data](https://roadsignmath.xyz/data): the feeds, the open files and the API for anyone building with the signs
- [Privacy](https://roadsignmath.xyz/privacy): what the game keeps and who sees it
- [iPhone app beta](https://testflight.apple.com/join/Httdw7ZY): the app, where the game is played, through Apple’s TestFlight

## Players

- [Jamie](https://roadsignmath.xyz/players/jamie): 13 signs in 5 states since 2021
- [Tyler](https://roadsignmath.xyz/players/tyler): 2 signs in 1 state since 2025
- [Tammy](https://roadsignmath.xyz/players/tammy): 1 sign in 1 state since 2021

## Signs

- [I-35W at 82nd Street](https://roadsignmath.xyz/signs/i-35w-at-82nd-street): (90 − 82) ÷ 8 × 1 × 2 = 6 ÷ (10 − 7). I-35W at 82nd Street, Bloomington, Minnesota, September 1, 2025. Found by Tyler.
- [On the way to the airport](https://roadsignmath.xyz/signs/on-the-way-to-the-airport): (25 − 1) ÷ 8 = 4 − 3 ÷ 3. On the way to the Burlington airport, Vermont, August 6, 2025. Found by Jamie.
- [Cancel it all out](https://roadsignmath.xyz/signs/cancel-it-all-out): (35 ÷ 7 × 10 + 12) − 62 + 6 + 3 + 2 = 11. I-35W south at Highway 62, Minneapolis, Minnesota, June 19, 2025. Found by Tyler.
- [Twin Lakes](https://roadsignmath.xyz/signs/twin-lakes): √(5 − 1) = 2. I-35 near Twin Lakes, Minnesota, October 22, 2023. Found by Jamie.
- [Mason Math](https://roadsignmath.xyz/signs/mason-math): 105 − 5 = 136 − 36. I-35 toward Mason City, Iowa, October 22, 2023. Found by Jamie.
- [Iconium](https://roadsignmath.xyz/signs/iconium): 7 + 12 = 19. Near Iconium, Missouri, October 22, 2023. Found by Jamie.
- [Osceola](https://roadsignmath.xyz/signs/osceola): 5 + 1 = 6. Near Osceola, Missouri, October 22, 2023. Found by Jamie.
- [Bolivar](https://roadsignmath.xyz/signs/bolivar): 10 + √4 = 12. Near Bolivar, Missouri, October 22, 2023. Found by Jamie.
- [Genesis](https://roadsignmath.xyz/signs/genesis): 3 × 33 = 99. I-94 east near Melrose, Minnesota, October 21, 2023. Found by Jamie.
- [Fair Play](https://roadsignmath.xyz/signs/fair-play): √(83 − √4) = 6 + 3. Near Fair Play, Missouri, October 19, 2023. Found by Jamie.
- [Fair Grove](https://roadsignmath.xyz/signs/fair-grove): 11 + √4 = 13. Near Fair Grove, Missouri, October 19, 2023. Found by Jamie.
- [Saratoga](https://roadsignmath.xyz/signs/saratoga): 14 + 10 = 24. On the way to Saratoga, New York, August 5, 2021. Found by Jamie.
- [Greenbush](https://roadsignmath.xyz/signs/greenbush): 9 + 11 = 20. Exit 11 to East Greenbush, New York, August 4, 2021. Found by Jamie.
- [Wurtsboro](https://roadsignmath.xyz/signs/wurtsboro): 12 + 1 = 13. Near Wurtsboro, New York, August 2, 2021. Found by Jamie.
- [Gross Vehicle Weight](https://roadsignmath.xyz/signs/gross-vehicle-weight): (70 ÷ (90 − 80)) + 13 = 65 − 45. Along I-80/I-90 East, July 31, 2021. Found by Jamie.
- [Phoenix Math](https://roadsignmath.xyz/signs/phoenix-math): 7 + 7 + (3 × 2) = 19 + 1. Loop 101, Phoenix, Arizona, March 4, 2021. Found by Tammy.

## Optional

- [Full text](https://roadsignmath.xyz/llms-full.txt): every sign in full: the numbers and what each was read from, every way and who found it, and what each photo shows
- [Sitemap](https://roadsignmath.xyz/sitemap.xml): every page
- [The first era](https://thingelstad.xyz/things/road-sign-math/): Road Sign Math from 2005 to 2014, on Things I’ve built
- [Licence](https://creativecommons.org/licenses/by/4.0/): the signs, the math, the places, the names and the photos are CC BY 4.0. Credit the sign’s finders and Road Sign Math, and link to the sign’s page.
- [Source code](https://github.com/jthingelstad/roadsignmath.xyz): this site and its API, MIT licensed