Why does the generic.txd file only work on this part of the map?

[SexAppeal]

I have inserted a file "generic.txd" that contains textures of palm trees and roads, the problem is that the texture of the road is only generated in a single part of the map as you can see below:

[Kelvin Garcia Mendoza]

It's because not all of road textures are used from generic.txd, only a few ones, like those in the screenshot. The rest of road textures are located in gta3.img. If this wasn't the case, generic.txd would be a lot larger than it usually is.