Transport noise is the dominant noise source in urban areas. In the UK, its impacts on people at their residential locations are included in project Business Cases, and guidance and analysis tools were developed for valuing the impacts through an impact pathway approach. However, for transport noise impacts on people in public urban spaces, e.g., urban streets, squares and parks, there is still a lack of national methodology. This paper will discuss the gaps, opportunities and challenges in developing a national methodology for valuing transport noise impacts in public urban spaces in the UK. Currently, evidence is lacking on how people are affected by transport noise at non-residential locations, and the values they place on sound environment quality at these locations. However, opportunities are emerging, with recent progress and transitions in urban sound environment research, and increasing attention to the urban realm in (UK) transport policy. The associated challenges, demonstrated with a case study project, may include: obtaining large and consistent data to estimate impact pathways, dose-response relationships and willingness-to-pay; estimation of affected receptors that are spatially and temporally dynamic; and noise modelling for the complex urban environment.