Despite a progressive increase of land value redistribution instruments anchored in federal and cantonal legislation, the implementation of developer obligations (DOs) and more broadly land-use planning legislation in Switzerland remains largely dependent on the local political context. This is reflected in the 2014 revision of the Federal Spatial Planning Act (FSPA), which introduced a value recovery mechanism whose implementation greatly varies among cantons and communes. As a result, the implementation of DOs largely remains case dependent. We show this phenomenon through a comparison of three urban projects promoted by the Swiss Federal Railways (SBB), where the negotiated obligations vary importantly across the cases. We find that the level of politicization of urban projects impacts significantly on authorities' willingness to negotiate DOs with the developer. A moderately politicized environment seems to be the most accurate configuration to implement DOs in Switzerland.