The calculated distance (air line) between Bourg-lès-Valence and Besançon is approximately 168 miles respectively 270 kilometers.
By car or train, the actual journey to Besançon is certainly longer, as only the direct route (as the crow flies) between Bourg-lès-Valence and Besançon has been calculated here.
Air line (approximately)
270 kilometers
146 nautical miles