The stone walkways are too limited and time consuming to place I think. They don't look so good in many situations and only come in that one color.
It would be so much better to be able to place paths that give road bonus and serve a purpose; especially if the paths blended in like the roads do and have curves, etc. The blended-in look would make them easy to place unlike the stone walkway that shows every pixel they are out of alignment.
I guess you'd need different colors to match snow and dirt plots and it would be fantastic if the footprint was as small as possible. They could aid the over-all plot design and functionality by providing faster paths for hauling materials around.