Water travel used to be the only form of transportation between cities in the Netherlands. Since improvements in the road and rail structure, less and less commercial freight water traffic is using the water. In the latter half of the 20th century the growth of water tourism exceeded the amount of freight traffic, and older cities whose ports were long disused refurbished them for water tourists. Water tourists are a strong lobby for protecting old water routes from being closed or filled. Both refurnished antique canal boats ("salonboten") and modern tour boats ("rondvaartboten") are available for tourist day trips in most Dutch cities. A steady tourist industry has kept both the old canals of Amsterdam and their canal mansions open for water traffic. Their popularity has introduced water traffic safety laws to ensure that the commercial passenger boats have right-of-way over private skiffs and low yachts, while preventing fatal accidents.