This paper focuses on the changes in transport accessibility at the regional scale in terms of individual car transport due to the introduction to the regional road network of the bypasses of Łódź in the meridian course. The changes are determined on the basis of measures of the time and potential accessibility of the network, conducted before and after the ring roads were implemented. The results are presented in both relative and absolute terms for each of the 4956 settlement units and 177 communes of the Łódź region. The author determines that the construction of motorways and expressways, especially those representing bypasses of large urban centres, helps to increase the cohesion of a region and increase accessibility of peripheral areas, while the size and spatial extent of the impact of road investments are clearly differentiated.
