The calculated distance (air line) between Spittal an der Drau and Bregenz is approximately 183 miles respectively 294 kilometers.
By car or train, the actual journey to Bregenz is certainly longer, as only the direct route (as the crow flies) between Spittal an der Drau and Bregenz has been calculated here.
Air line (approximately)
294 kilometers
159 nautical miles