A diagram showing facing points
<a href="//commons.wikimedia.org/wiki/User:Thryduulf" title="User:Thryduulf">Thryduulf</a>
CC SA 1.0
Own work based on: <a href="//commons.wikimedia.org/wiki/File:Kierownica.svg" title="File:Kierownica.svg">Kierownica.svg</a> <i>by</i> <a href="//commons.wikimedia.org/wiki/User:Swisstack" title="User:Swisstack">Swisstack</a>