We study the determinants and productivity effects of regional transportation infrastructure investment in France, Germany, Italy, and Spain. We estimate productivity effects with regional production functions for each country controlling for the potential endogeneity of public infrastructure investment. In analyzing the determinants of public infrastructure investment two broad categories are considered: First, the normative principles such as efficiency, equity, and redistribution; and second, political factors such as electoral competition and electoral rents. The evidence shows that road infrastructure positively contributes to regional production. As to the determinants, efficiency and redistribution are consistently found to be the dominant norms while equity considerations appear to be less important. However, we find remarkable differences across countries regarding the political determinants. Which political factors matter for infrastructure investment is related to the different political systems of the various countries.