The transport service market is a demand-driven market. Freight rates are volatile and subject to
seasonality. According to CAIXETA-FILHO (2003, p. 1) "freight prices are formed through free negotiation
determined by supply and demand for the transport service". The rates are composed by
the transport costs and a profit margin of the service provider. The seasonal supply/demand relation
may increase or decrease the profit of the transportation company (JESUS, 2012).