Territorial and Functional Concentration and Directed Departmental Structure of Colombian Road Freight Flows: RNDC Evidence for 2022–2025

Background: Administrative freight records can support repeated territorial analysis when their aggregation grain and measurement units are explicitly distinguished. This study analyzes Colombia’s National Registry of Road Freight Dispatches (RNDC) from January 2022 to December 2025. Methods: Territorial and functional concentration were measured separately by direction using represented trips and mass-recorded tonnes. Raw and normalized Herfindahl–Hirschman indices, effective numbers, supplementary Shannon measures, month-resampling and leave-one-month-out stability diagnostics, as well as directed interdepartmental density and reciprocity, were calculated. Results: Across the four years, 8,176,619 monthly aggregate source rows represented 46,969,693 trips. Represented trips increased from 10.28 million in 2022 to 13.24 million in 2025 (28.8%), whereas mass-recorded freight increased from 135.76 to 151.52 million tonnes (11.6%). Territorial concentration followed direction- and measure-specific, non-monotonic trajectories. Directed density was 0.827–0.841 and binary reciprocity was 0.939–0.954, compared with weighted reciprocity of 0.643–0.701. Trip-versus-tonne HHI rankings had Spearman correlations of 0.535–0.823 and a maximum departmental rank difference of 26. Fixed-versus-observed normalized-HHI rankings had correlations of 0.761–1.000 and a maximum rank shift of 30. Conclusions: Registered Colombian road freight combined broad binary connectivity with heterogeneous concentration. The framework supports comparative screening, while infrastructure or causal interpretation requires independent evidence.