The paper examines changes in economic activity occurring in municipalities around the motorway D11, after a new section of motorway has been opened in 2006. The aim of the paper is to determine the extent to which the detected changes in the region can be connected with the opening of the motorway section. The changes in establishment and extinction of firms with distinction by industry sector are evaluated using descriptive analysis and Difference in differences method. The results of the research show certain manifestations regarding the opening of the motorway, since the changes in firm birth intensity are the highest in the group of municipalities that are within 8–12 min' drive from the motorway, and with increasing distance from the motorway the intensity decreases. The link with the proximity of the motorway indicates increase of firms in general, within sector categories it stands for manufacturing industry, construction and logistics. At the same time, for municipalities at the distance of 12–20 min away we recorded slight decrease of firm birth intensity in comparison to a period before opening of the motorway section. These results indicate that the main road infrastructure positively influences only the nearest area. •Birth rate of firms grew faster in municipalities around new opened motorway.•Municipalities 8–20 min from motorway experienced decrease in firm birth rate.•Manufacturing, transport, and construction sectors seem to be most influenced.•Firm birth rate on original main routes also influenced by transit traffic decrease.•Original main route more distant to motorway experienced more negative changes.