Hilly topography doesn't really make it prohibitively expensive to make 2+1 roads, or at least they're relatively common in Finland. (Although 2+1 roads are rar

Hilly topography doesn't really make it prohibitively expensive to make 2+1 roads, or at least they're relatively common in Finland. (Although 2+1 roads are rarely separated by fence here). Even hilly roads tend to have straight sections that can serve as the 2+1 area.