The calculated distance (air line) between Changyŏn and Chaeryŏng-ŭp is approximately 30 miles respectively 48 kilometers.
By car or train, the actual journey to Chaeryŏng-ŭp is certainly longer, as only the direct route (as the crow flies) between Changyŏn and Chaeryŏng-ŭp has been calculated here.
Air line (approximately)
48 kilometers
26 nautical miles