2d isometric path set into a certain sprite like road sprite

Hi friends. Need your help. I want to build an 2d isometric game. I want from object ( car) to move only on road sprites. How can i do that . I know there are a waypoint system. But i want i think its gonna be a long for building levels. But i want to store a data into a sprite (Road) an information that when there is aroad sprite car will know that road is his path. I think that better way is to create a scriptable object (road) and set into it a waypoint. But maybe i am wrong and i want to know a right way how to do this. Or maybe make a scriptable object and make it a walkable? Please Help !!! )