CurbTXT allows anyone to send texts to drivers in San Francisco. The service lets people register their license plate numbers to an online database so others can send them a message if there is a problem.

It was launched to be an altruistic way for people to communicate when someone’s car alarm is going off, their car is blocking a driveway, their lights were left on, etc. The instant and direct communication is anonymous and one-way, so drivers don’t know who sent the message and can’t reply.

To use the service, drivers need to register their license plate, save the CurbTXT number in their phone, and affix the CurbTXT sticker next to their rear license plate so neighbors know how to alert them if there’s an issue.

To send a message to a registered vehicle, anyone can simply text the license plate starting with the state abbreviation to CurbTXT. For example, “CA3214567 you’re blocking my driveway – pls move”. Inappropriate messages can be flagged and users blocked by texting back #block and CurbTXT will investigate.

CurbTXT