According to Ktimatologio (the Greek land management database), this road is National Road 53.

National Road 53 goes continues through Dereio-Metaxades-Ladi-Kyprinos-Komara-Pentalofos-Petrota-Ormenio.

The road is also called Διδυμοτείχου-Μεταξάδων, but it still functions as the National Road 53. It's not a different road, it's a continuation.

maps.ktimatologio.gr