The calculated distance (air line) between Ḩarastā and As Salamīyah is approximately 108 miles respectively 173 kilometers.
By car or train, the actual journey to As Salamīyah is certainly longer, as only the direct route (as the crow flies) between Ḩarastā and As Salamīyah has been calculated here.
Air line (approximately)
173 kilometers
94 nautical miles