Thanks to the following who e-mailed images or mailed photos:
Thanks to the following who provided corrections and other information:

Special thanks to Wei-Hwa Huang for giving me the images with which I started.

The Sources page describes where these people got the images.

And, of course, thanks to everyone who e-mailed comments and suggestions. The response has truly been more than I ever expected. Who would think so many people would be interested in road signs?