The calculated distance (air line) between San Martino Buon Albergo and Mestre is approximately 56 miles respectively 90 kilometers.
By car or train, the actual journey to Mestre is certainly longer, as only the direct route (as the crow flies) between San Martino Buon Albergo and Mestre has been calculated here.
Air line (approximately)
90 kilometers
49 nautical miles