The ability of transplanted lichen Pseudevernia furfuracea to biomonitor specific airborne pollutants (heavy metals and polycyclic aromatic hydrocarbons—PAHs) was investigated at five stations with different traffic densities in Viterbo, Italy. Exposed lichen showed high levels of all analysed pollutants; greatest values were for Zn (147–252 μg/g dw), Pb (24.9–34.6 μg/g dw), fluoranthene (37–107 ng/g dw), pyrene (23–124 ng/g dw). Comparison between contaminants concentration in lichens before and after exposure showed “accumulation” or “severe accumulation” rates in more than 90% of each substance. Besides, Pseudevernia furfuracea accumulated airborne PAHs in a manner that was proportional to traffic density.