Cost efficiency and flexibility have become increasingly important in the logistics of cut-to-length harvesting operations. At the same time, the operating conditions for long-distance transportation have become more demanding and variable. Since the number of log products has increased and the size of harvesting sites has decreased, loads of timber must increasingly be collected from several log decks, increasing the time consumption and costs of the trucking operation. The objectives of this study were to formulate time-consumption models for typical timber transportation activities in Finland and introduce a statistical procedure for examining the variation in time consumption during the trucking phases. The study used a combination of time studies and follow-up studies based on empirical data for 368 loads (a total volume of nearly 18 000 m3) collected from one wood procurement district in central Finland. The model included the following explanatory factors: driving distance, number of log decks, log product and load volume. Since transportation includes several phases and since many factors affect the work performance, significant variation in the total transportation time was observed. This makes planning and cost accounting more difficult. The models developed in this study are a promising initial tool to support route planning and optimization, and cost and profitability calculations for trucking entrepreneurs and the forest industry.