What to call this type of temporary arrangement on the road?
Solution 1:
The structure you are looking for are called stepping stones. The name is applicable to any walkway of that type, whether temporary or permanent.
Solution 2:
It's "an improvisation" or an improvised solution
- Improvisation is the process of devising a solution to a requirement by making-do, despite absence of resources that might be expected to produce a solution.
- Improvised (adj) done or made using whatever is available.
an improvised bridge, for example
