The paper analyses why CO2 emissions from heavy road freight transports increase in spite of higher fuel prices. Swedish time series data for 1990-2011 are analyzed with help of indicators. The logistic efficiency and the energy efficiency improved, especially in the 1990-ties due to the allowance of heavier trucks. Since then no major efficiency gains have been realized. Potentially cost effective technologies exist but technical, institutional and financial barriers reduce the incentives for the transport firms to imply these. Split incentives caused by contract structures or ownership patterns can impede the employment of the technologies. If fuel savings are realized rebound effects can appear that cancel out improved energy efficiency. Deeper knowledge of the impacts of policy measures is required in order to understand why CO2 emissions increase despite increased fuel prices. A better understanding of the model simplifications in the Swedish national model Samgods is also needed as well as an analysis of what is required to better mirror the contracts that we observe in reality.