The anticipated benefits of new transportation infrastructure are commonly assessed in feasibility studies through the examination of current traffic data and derived theoretical predictions. In the field of geoinformation, accessibility maps, such as isochrones, are frequently employed to spatially visualize travel times. This article introduces a methodology for calculating the impacts of new public transportation routes on travel times and compares various approaches for representing the results in maps. The integration of both real and simulated schedule data into a unified computational model enables the direct portrayal of time savings resulting from the introduction of the investigated new route into an existing public transportation network.