Road freight transport decarbonization is an important element in the global agenda. There is a large body of literature addressing operational research solutions and optimization. However, it is not clear whether the actual sector can be reactive to policies to promote its decarbonization. Even more when the sector is pressured by its clients and upstream supply chain trends, and seems not to have any room for enhancement. In order to further understand the sector’s potential to improve its productivity, a system’s dynamics diagram is developed. Moreover, an analysis of the Spanish road freight sector with quarterly data from 2000 to 2023 is carried out using a vector error correction model. Results suggest that the sector’s productivity, in ton-km, is reactive in the long-term to diesel prices, by producing a lasting reduction ton-km. However, the long-term response to an increase in transport prices might increase the total ton-km.