peer reviewed ; This paper examines regional differences in commute-energy performance in Belgium, and explores their relationships with spatial characteristics such as the distribution of population and housing, the metropolitan influence of the Brussels agglomeration, and the compactness of cities and towns. We also investigate contradictions between Belgian state-wide commute policy and regional differences in average commuting distance and mode choice. Against a background of long-term federal measures that traditionally encourage long-distance commuting in Belgium, we find striking discrepancies between the structure and the development of commuting patterns in the three administrative regions of Flanders, Wallonia and Brussels. Residents of Brussels show the most sustainable commuting patterns, due to the metropolitan spatial structure. Residents of Wallonia represent the least sustainable commute. Given the rather weak regional economy of Wallonia compared with Flanders, commuters must frequently seek employment far from their residence. Population changes and consequent developments in the housing market seem to exacerbate this competitive disadvantage, since most growth occurs in relatively remote rural areas that are nevertheless within reach of the main employment centres. ; Thème 2B - Impact de la structuration du territoire sur les émissions de GES