---
title: "3M Puts Invisible Notes on Street Signs to Help Self-Driving Cars"
description: "The notes help autonomous cars \"see\" where they are."
date: "2017-08-17"
modified: "2017-08-17"
authors:
  - name: "Stephen Edelstein"
    job_title: "Weekend Editor"
    link: "https://www.thedrive.com/authors/stephen-edelstein"
url: "https://www.thedrive.com/tech/13563/3m-puts-invisible-notes-on-street-signs-to-help-self-driving-cars"
categories:
  - "News"
tags:
  - "3m"
  - "Autonomous Cars"
  - "road signs"
  - "secret messages"
  - "self-driving cars"
---

# 3M Puts Invisible Notes on Street Signs to Help Self-Driving Cars

![](<https://www.thedrive.com/wp-content/uploads/images-by-url-td/content/2017/02/speed-limit-sign-hero-ohio.jpg>)
*\<em\>www.thedrive.com</em>*

Recently, security researchers found a way to mess with self-driving cars by [placing stickers on street signs](<https://www.thedrive.com/tech/13258/researchers-fool-self-driving-cars-with-stickers-on-street-signs>). But now 3M—the company behind Post-It Notes and Scotch Tape—wants to use a similar technique to help them. 3M is placing invisible notes on street signs to help autonomous cars "see" where they are, according to [*Business Insider*](<https://www.businessinsider.com/3m-hides-tech-in-sides-to-help-general-motors-self-driving-cars-2017-8?mc_cid=b4a20554db&mc_eid=886267cfd9>).

The company is testing stickers that appear virtually transparent to the naked eye, but actually contain "bar codes" that self-driving cars can read. These bar codes can contain information like GPS coordinates, or the location of nearby traffic lights. The idea is to give self-driving cars an extra source of information to supplement data from their sensors and digital maps, providing a redundant way for cars to keep track of where they are.

3M partnered with the Michigan Department of Transportation to install its bar codes on work-zone signs and road workers' vests on a three-mile stretch of Interstate 75 near Detroit. The stickers are designed to warn self-driving cars of work zones so they know to slow down. General Motors is testing Cadillac CTS sedans in the area [equipped with vehicle-to-infrastructure tech](<https://www.thedrive.com/article/8250/2017-cadillac-cts-to-feature-v2v-communication-as-standard>) that allows them to read the messages, although the cars aren't autonomous.

Self-driving cars will need all of the help they can get to navigate our chaotic world, so putting stickers on street signs seems like a fairly simple way to improve their situational awareness. Because no one wants a confused robo-car.

(Below, a visual illustration of how semi-autonomous systems—in this case, Tesla's Autopilot—"sees" the world around the car.)

## Author
Stephen has always been passionate about cars, and managed to turn that passion into a career as a freelance automotive journalist. When he's not handling weekend coverage for The Drive, you can find him looking for a new book to read.

### Author social links  
[Twitter](<https://twitter.com/SAEdelstein>)