In this article, I offer speculations which share the intentions of this symposium to bring to light seldom acknowledged configurations of knowledges, and to indicate different ways of thinking historically about urban problems and planning policies. I suggest that a genealogical or critical historical sensibility has much to contribute to these projects by tracing how policies and programmes come into being in response to specific conditions and within specific sets of presuppositions, and are rarely the products of unified histories or singular rationalities. But these policies are also configured in discursive terrains that already shape the form of problems and their possible solutions. That is, before policies or concepts can ‘travel’, they have to come into being under certain ‘conditions of possibility’. The main focus of this article is to suggest that posing a policy, programme or set of practices as a ‘problematization’ as a consequence of certain conditions of possibility can productively indicate different avenues of enquiry that trace the disparate ‘pre-travel’ emergences of what may (or may not) then become ‘travelling’ policies. I indicate some questions and possible research directions arising from taking participation in planning as a particular form of problematization and calling attention to the taken-for-granted nature of ‘participation’ as it is theorized and practised in the fields of urban planning and participatory development.