measuring distance of branching pattern

Hi, i experimenting with l-systems for creating branching patterns, im interested in using branching structures for designing pathways for a forest.

But i have a question, i have a book that says:

"Branching patterns are an efficient way to reach all the points in a large area, while moving the shortest distance possible."

... I was wondering, how can i measure this? how can i measure the distance of a branching structure? how can i know which branching pattern is more efficient ?

I would like to create different branching patterns and then compare them based on their distance.

Is there an algorithm or a way for comparing a group of branching patterns in order to know in which one you need to move the shortest distance possible?
how can i measure this?

any idea?