The calculated distance (air line) between Ar Rumaythīyah and Az Zawr is approximately 15 miles respectively 24 kilometers.
By car or train, the actual journey to Az Zawr is certainly longer, as only the direct route (as the crow flies) between Ar Rumaythīyah and Az Zawr has been calculated here.
Air line (approximately)
24 kilometers
13 nautical miles