The calculated distance (air line) between Wijk bij Duurstede and Haarlem is approximately 41 miles respectively 66 kilometers.
By car or train, the actual journey to Haarlem is certainly longer, as only the direct route (as the crow flies) between Wijk bij Duurstede and Haarlem has been calculated here.
Air line (approximately)
66 kilometers
36 nautical miles