The calculated distance (air line) between Tallkalakh and Ḩalfāyā is approximately 45 miles respectively 73 kilometers.
By car or train, the actual journey to Ḩalfāyā is certainly longer, as only the direct route (as the crow flies) between Tallkalakh and Ḩalfāyā has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles