Transportation of renewable wood is increasing, being a necessary operation in logistics of the environmentally sustainable forest industry. However, increasing the transportation capacity is a source of greenhouse gas emissions. In addition to trucks’ emissions, maintaining road infrastructure affects the environment by the emissions of increasing utilization of HCT (high-capacity transportation), that is, larger and heavier vehicles, affecting the backhauling transportation and the efficiency of road-network combinations. Environmental efficiency is an important metric which is used for comparisons among technological alternatives employed in the utilization of energy derived from both fossil and renewable resources. Based on the enterprise resource planning (ERP) data (2018−2020), CO2 emissions of increasing HCT were calculated for a forest industry corporation. The reduction in average fuel consumption (ml t × km−1), between 52% and 70% in backhauling transportation, was 18.88%. In this respect, CO2 emissions were reduced by 4.52 g t × km−1, achieving 19.48 g t × km−1, based on the data from the 76 t vehicle combinations. Furthermore, the metric of total environmental efficiency shows the potential of the alternative road-network combinations for the HCT. The environmental efficiency of the 92 t HCT increased by 11% via an intensive road-network combination, compared to the most efficient 76 t HCT alternative and the efficiency increased by 21%, compared to the most efficient line-hauling alternative. Thus, the results are in favor of the backhauling transportation by the means of 92 t vehicles for HCT development. Furthermore, a sensitivity analysis demonstrates that technological improvement of the forest roads is essential for HCT in an increasing harvesting of renewable wood energy. Also, to achieve the maximum environmental efficiency of the HCT during upgrading of the forest roads, efficiency measurements of the HCT should be implemented in the transportation planning systems.