Economic effects of transport infrastructure are often expressed in terms of productivity and employment differentials, whereas comparatively less attention has been devoted to impacts on firm location and birth. The aim of this paper is to contribute to existing literature by studying the construction of the highway network in Italy in a counterfactual approach. In particular, the role of endogeneity of exit location is explicitly considered and addressed by means of a new variable measuring the geography of the Roman network. Our results indicate that an improvement in accessibility as proxied by the location of an exit in the city has a positive impact on the employment rate and on plant birth, with larger impacts in Center-northern and smaller cities.