A red and blue street sign in Mainz-Lerchenberg. The red street signs show streets which have a vertical relation to the Rhine. The blue signs show streets have a horizontal relation to the Rhine.
<a href="//commons.wikimedia.org/wiki/User:PantheraLeo1359531" title="User:PantheraLeo1359531">PantheraLeo1359531</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>