In this essay we argue for what we term ‘dynamic evaluation’ of transport policies. In a time of increasing political polarization of public transport, dynamic evaluations involve a broader scope of factors and indicators, including political processes and justice, compared to traditional evaluations typically centered on ridership. We illustrate this perspective by discussing the experiment of free public transport provision in Stavanger, Norway during July-December 2023. Planned and budgeted for a year shortly before local elections, the intervention was repealed halfway through, as the new governing political coalition held that this was a sub-optimal means to deliver public transport policies. We contrast a traditional commissioned evaluation of how the experiment modestly increased ridership with a dynamic evaluation involving broader political and justice processes, to illustrate that the experiment contributed to politicizing public transport in potentially transformative ways.