In Joensuu, Finland, a new bridge, Sirkkalansilta, was to be built. In this work, we study its effect on the working population’s commuting traffic. We investigate, with the working population census data, the traffic flow conditions of without and with the new bridge using multi-agent traffic simulation. We also investigate the correlations of the bridges with regards to bridge closures. Actual hourly bridge usage data was collected by Joensuu city council after Sirkkalansilta was opened to traffic. We compare our simulation with the collected hourly bridge usage data to conclude on the feasibility of using multi-agent traffic simulations for real world application and propose how it can provide suggestions on future improvement.