Hello.
I'm specialist in image processing, so I can easily solve your project.
There is an easy way to make it in several steps:
- detect roads by color first.
- make a binary mask basing on color.
- filter out "noises" such as buildings of same color as roads.
- thicken mask to stay sure we'll not cut off piece of highway
- that's it!
I will write a fully commented code, so you will easily understand each step of the algorithm. Contact me, if you are interested, and we'll discuss details.
Thanks for your attention.