I was thinking of doing something similar to this in a later version of zombies, it'd be pretty simple though.
Basically a zombie/bot acts normal until it comes across one of these nodes, goes to it, when it reaches the node, it then goes in the direction specified by the arrow, then looks for another node, if none is found it just starts randomly walking again.
Not sure when this will come since I have a lot of ideas for zombies, and I have some other things to work on at the moment.