Randomly selecting from SPECIFIED tiles in a Tilemap instance

I have a single instance of a tilemap object with all the road-themed tiles in place.

From those tiles on the tilemap instance, I want to select only specific tiles and then randomly select one of those tiles.

What would be an efficient way to do that?

You can loop over all the tiles and use an array to make a list of xy positions where a road tile is. Then you can pick a random xy pair from the list.

Looping over all the tiles can be time consuming so instead of doing that every time you can just maintain the list of road tiles and update that when you add or remove road tiles.

Alternatively you could use sprites instead of those tiles. Sprites are great if you want to pick a specific one. Arrays and tile maps are great for accessing things at specific spots.