Learn Something New Everyday: Trap Streets 

Trap streets are a practice used by map companies, to detect copyright infringement. When making maps, a few insignificant errors are included. If the map is copied verbatim, these fictitious streets will come along for the ride, and can be used to prove infringement.

Most examples of trap streets are found in England and other parts of Europe. Ian Betteridge has a good example of a trap street, in Canterbury. The satellite view shows that it’s actually going into a house:

A trap street in England

The Straight Dope also has an old but excellent overview of the practice. From now on, I’m following the lead of Straight Dope’s Cecil Adams. As such, I will no longer be making mistakes – only copyright traps.