In a previous paper, we reported synthesis, structural characterization and multichannel anion sensing studies of two pyrene-biimidazole based monometallic complexes of the type [(bpy)₂M(Py-BiimzH₂)]²⁺ (M = Ru^II and Os^II), where Py-BiimzH₂ = 10-(1-H-imidazole-2-yl)-9H-pyreno[4,5-d]imidazole and bpy = 2, 2′-bipyridine. Photophysical and redox properties of the complexes were found to modulate significantly with selected anions. In present work, we will demonstrate that this family of the complexes can mimic the rare function of traffic signal based on the degree of optical spectral changes upon sequential addition of selected anions (H₂PO₄⁻, CN⁻) and proton. In addition, based on the absorption and emission spectral profiles towards a specific set of ionic inputs, the complexes nicely demonstrate the functions of several important logic gates (OR, NOR, INHIBIT and IMPLICATION) as well as memory device.