Andrés Felipe Rey

The Colombian road freight transport sector is a major contributor to greenhouse gas (GHG) emissions and plays a critical role in achieving the country’s net-zero target by 2050. While technological solutions such as vehicle electrification and alternative fuels are essential, substantial mitigation potential also lies in improving operational efficiency. A persistent source of inefficiency is the prevalence of empty trips, cargo-free freight movements that increase logistics costs, reduce fleet utilisation, and generate avoidable emissions.
This study addresses empty trips from a national, system-level planning perspective by introducing a spatio-temporal synchronisation model that identifies opportunities to coordinate independent freight movements travelling in opposite directions based on temporal and spatial compatibility. By relying on aggregated information rather than firm-level routing optimisation, the model enables scalable coordination across the freight network without requiring centralised control.
Two algorithms were developed to estimate current empty-trip rates from observed trip sequences and the minimum achievable rate under ideal synchronisation. Applied to more than 7.99 million trips from Colombia’s National Freight Registry, the results indicate that synchronisation could reduce empty kilometres by up to 39.34% for light and medium-duty vehicles and 37.37% for heavy-duty vehicles, corresponding to an estimated annual reduction of 130,470 tons of CO2e.
The study also introduces the concept of structural residual empty trip revenue (SRETR) to assess the economic potential of empty trips that remain unavoidable under optimal coordination. These insights support policymakers in prioritising interventions, addressing regional freight imbalances, and integrating operational efficiency measures into national decarbonisation strategies.

This study introduces a simulation-based analysis of the decarbonization options for the road freight transport sector. It focuses on exploring the impact of operational and management measures on fleet renewal strategies aimed at achieving net zero goals by 2050. The proposed approach integrates current and planned future policy changes, operational practices, and technology renewal into the modeling process to offer a macro-level perspective on the decarbonization challenge. Specifically, the proposed modeling approach takes into account the reduction of empty trips, the optimization of cargo consolidation, and the promotion of eco-driving practices based on national freight transport data (i.e. covering more than 7.99 million trips). The proposed approach examines the effect of introducing contemporary vehicle technologies, such as new diesel vehicles (EURO VI or higher), new natural gas vehicles (EURO VI or higher), electric vehicles and hydrogen vehicles, as feasible replacements for aging vehicles powered by conventional fossil fuels. The adoption of these cleaner and newer technologies demonstrates the potential for emission reductions of up to 13% (2,070,000 tons CO2e) by 2030 and 47% (13,232,000 tons CO2e) by 2050. In addition, the results obtained from this research can serve as an exemplary case study for other emerging economies.