There are a number of variations on what RET could be. Road Equivalent Tariff (RET) usually involves setting ferry fares related to, but not necessarily equivalent to, the cost of travelling by road. Ferry fares have been seen by many as a barrier to economic growth on the islands. It is argued that lowering the fares to a level broadly similar to mainland traffic costs could act as a boost to island economies by reducing freight costs to local businesses, lowering the cost of living for island residents and making the islands more attractive to tourists.