3M is developing road signs that have specially printed bar codes for self-driving cars, according to Business Insider. This is a clever entry in the vehicle-to-infrastructure communication field.
Often that’s thought of as infrastructure and vehicles communicating back and forth electronically. But this approach, in which the road signs simply have specially encoded information, is much simpler and presumably cheaper.
The article is light on details of how exactly the barcode is written onto the sign, although supposedly the barcode is invisible to humans. Even without that requirement, though, you could imagine tagging each road sign with a small visible barcode, the same way canned goods have barcodes.
Information on the barcode can include the type of sign, of course, but also the GPS coordinates, which would be super-helpful for localization. Other information, about upcoming waypoints or intersections, could also be valuable.
Pretty simple, but effective, and cheap and easy to roll out.