Rotterdam has to reduce emissions and different interventions are being implemented to contribute to the mission of achieving a sustainable, energy-efficient Rotterdam, with improved air quality. An unidentified intervention is the implementation of a car-free city centre which might be perfectly applicable in the specific case of Rotterdam. This research will focus on the societal feasibility of a car-free application and important monetary elements defining the feasibility. Based on insights derived from gained results, lessons can be learned for future developments. Therefore, the following research question will be researched: Which policy lessons can be learned from societal cost-benefit results of a car-free city centre intervention in Rotterdam? Car-free project alternatives are created as input for a Cost-Benefit Analysis (CBA). Valuated effects are incorporated in the CBA per project alternative to approach important effects and the societal feasibility of a possible car-free implementation. Based on the attempted CBA estimations, a car-free city centre is not feasible in each given project alternative. However, the CBA results can be used as a design instrument by using insights, derived from created configurations wherein input variables are altered, to create a more optimal project alternative. Travellers value car utility highly resulting in major costs. Major benefits can be achieved by an increased amount of commuters switching from the car to the bicycle. In order to create a more optimal project alternative, it is advisable to stimulate public transport usage and reduce the loss on car utility related effects and thereby be traffic-calm instead of car-free.