Fallout 4 should eventually be a truly excellent game thanks to mods like this one, which greatly improves upon the green blurriness of the game's Pip-Boy map. While there isn't a huge improvement, the mod does show roads more clearly.
Succinctly called the Improved Map with Visible Roads mod, it adds a great deal more definition to the map than is available in the un-modded "vanilla" version of the game by upping the contrast. There is also the option to display a version of the map between the modded version and the original.
The modded map is only available through the in-game Pip-Boy interface, but not the real-world special edition wrist-mounted Pip-Boy, which houses a phone on which the player uses a separate app. The in-game Pip-Boy and overall UI has been criticised since launch for its clunky, obtuse menu system. The map, which is little more than a green blur with icons on it, is another big problem.
You can read our review of Fallout 4 here.