The calculated distance (air line) between Kampong Speu and Svay Rieng is approximately 90 miles respectively 145 kilometers.
By car or train, the actual journey to Svay Rieng is certainly longer, as only the direct route (as the crow flies) between Kampong Speu and Svay Rieng has been calculated here.
Air line (approximately)
145 kilometers
78 nautical miles