The problem of the traveling salesman is a useful approach to determine the most efficient [shortest length] routes to take within a given transportation network.  In this exploration, I used the streets of downtown Rochester as the network and all the intersections as start and end points of a desired route.

Giulio Piacentino with McNeel Europe created a Grasshopper component that attempts to solve this problem.  Here is the aerial image of downtown Rochester:

Below are all the intersections:

…and from the intersections is the network of street.  This network includes all the possible routes one could take  from any intersection to another.

The simple grasshopper definition below allows testing of almost an endless number of paths.

This animation demonstrates a selection of random start and end points [connected by a yellow line], and draws the shortest route from one to the next by following the streets [red lines].

Rochester | shortest street routes from 2 points from Jie Huang on Vimeo.