The calculated distance (air line) between Hihyā and Kawm Ḩamādah is approximately 53 miles respectively 86 kilometers.
By car or train, the actual journey to Kawm Ḩamādah is certainly longer, as only the direct route (as the crow flies) between Hihyā and Kawm Ḩamādah has been calculated here.
Air line (approximately)
86 kilometers
46 nautical miles