Distance limited curves in VB

Hi, I'm looking for a plan of attack for a analysis method I'm wanting to try out.
I've modelled a basic road network and from a selected start point I want to traverse down a number of path options until reaching a set distance and stopping.

I'm thinking that I can take a set of curves dividing them by length, then find the closest points along the paths, measuring the distance as I go, stopping once the max distance is reached. My problem is that I don't know how to direct the path down alternate routes at intersections. Any help would be greatly appreciated!

Cheers,
David