3rd experiment on photoshop

Although i think visually this is getting much better i need to keep developing this to ensure the area i am revealing in removing the white arrow doesn't become darker than the surrounding area.
I also want to look at how i can make the arrow fade from the outside initially.

To achieve the effect above. I used a variety of selection tools to make an exact duplicate of just the arrow on two new separate layers. The top one remained the exact colour of the one it was copied from.
The middle layer arrow was then filled in with tarmac (from the original image beside the arrow)
This meant that when I used blending options and the eraser tool with a textured brush to remove areas of the top arrow the tarmac beneath was revealed.

For my next experiment i plan to repeat the process of duplicating the arrow but this time I will make three copies of just the arrow, each on separate layers. The one directly on top of the original image will be blacked out with tarmac, the one on top of that will be an exact duplicate of the original, and the final top arrow will also be a duplicate of the original arrow but with the edges faded away and slightly rescaled to be smaller than the white arrow below it. I will then fade away the larger arrow gradually then the smaller one. It will be a a longer process but i hope it will give the impression of the outside fading first, as my research has indicated that a lot of road signs are designed to do this so they last longer.
Basically they first of all peel away from the outside leaving the original shape, just smaller but still distinguishable, then the rest wears away also.