I have a really tricky problem here and I'm hoping that there is a math guru here who can help.

**The problem**

Using Google maps, I need to allow a user to draw a line. This line can be in any direction and basically, I need to determine if the user has drawn the line over a road and if so, how many.

Below is an example:

The image doesn't seem to be showing so here is the link:

**View image: map basic**

With Google Directions service, I am able to get the nearest road the the dropped marker (markers indicated by arrow in image).

For a single road, I believe that I can do this with Pythagoras, but for multiple roads by brain starts to boil.

If anyone here could help, I'd really appreciate it. I appreciate it is pretty tough so I'm open to all suggestions.

Thanks!