to run out of road

are likely to use up all of the available options.

Off the pavement, and onto a rough terrain.

The situation in the Balkans is incredibly complicated. Standard diplomatic negotiations (the road) can only go so far.

Eventually the diplomats are going to have to leave the road, abandon precedents and head out into uncharted wilderness.

Very well put, Noddy.

Joe(got it)Nation

Comprehension is based on logical imagination
Dear noddy24
I thank you very much for the paraphrase you give me here. I think everyone will agree that correct comprehension is based on logical imagination.
I will translate as you suggest.

I think it means

to run out of options,

- or -

will come to a standstill since they have no place to go.