The calculated distance (air line) between Pyŏksŏng-ŭp and P’yŏngsŏng is approximately 85 miles respectively 136 kilometers.
By car or train, the actual journey to P’yŏngsŏng is certainly longer, as only the direct route (as the crow flies) between Pyŏksŏng-ŭp and P’yŏngsŏng has been calculated here.
Air line (approximately)
136 kilometers
73 nautical miles