At the Tripoint of the Balkans (Hungary, Romania, Serbia – located near Szeged), there is a border crossing station between Hungary and Serbia (apparently opened a few years ago), yet there doesn't appear to be a Romanian one. The Romanians however built a new road to the Serbian border, where a 'Republic of Serbia - Welcome' sign is located next to the road, and the road briefly turns into a path until it reaches the road from Hungary to Serbia. (C.f. linked satellite imagery and fairly recent StreetView imagery on the Romanian road.)
Given the 'Welcome' sign: Can the Serbian-Romanian border be crossed there by some sort of special arrangement, even though the Romanians do not appear to have a border crossing station there?