It isn't a single word but road to horizon is used as a phrase. You can find similar images if you search it on Google Images:
I know that roads are usually depicted as vanishing into the horizon but this phrase is self-explanatory. Similarly, road to nowhere is used as a metaphor also for vast roads that seems endless and vanishes into the horizon. It sounds rather poetic though.
Example usage:
Freshwater Road went somewhere, though when you stood outside, it seemed to be a road without end, or a road to nowhere, just narrowed into its own horizon.
[Freshwater Road By Denise Nicholas (2005)]
Note: Road to nowhere is usually used for a situation or course of action offering no prospects of progress or advancement. [oxforddictionaries]