This paper contributes to the study of linguistic landscapes by analysing warning and prohibition signs in urban settings. On the basis of data collected in British cities, it explains how directive signs reflect the interplay of language, law, space and society. Primarily conceptual in orientation but with a strong empirical base, the paper explores how the performativity of directive signs is constituted, on the one hand, by where they are placed, and, on the other, by implicit or explicit references to legal authority. By taking a socio-legal perspective, and considering the intertextual links between signs and the legal code, the paper addresses issues hitherto neglected in linguistic landscape research.