This study uses oriental plane (Platanus orientalis L.) leaves to determine the heavy metal pollution caused by vehicular traffic on the D-755 Highway connecting Bartın and Karabük cities in Turkey. As a result of the analyses, it was determined that the order of elements leading to metal emitted from vehicles is Pb>Zn>Ni>Cu>Cr>Cd. On the other hand, according to the variance analysis and Duncan test performed, we found a statistically significant difference between 20 sampling stations at the confidence level of P<0.01. Accordingly, while stations 1, 2, 3, 4, 10, 11, 17, 18, 19, and 20 were in the first group in terms of heavy metal pollution, stations 5, 6, 7, 8, 9, 12, and 13 were in the second group, and stations 14, 15, and 16 were in the third group. Moreover, it was determined that injuries at dimensions of 1.5-4.7 μm occurred in epidermis cells of the oriental plane trees’ leaves, and that the dimensions of these injuries reached levels of 10.2-14.7 μm during further periods. Actual levels of trace elements are as follows: Pb 0.10-0.78 mg·kg^-1, Zn 18.2-52.4 mg·kg^-1, Ni 0.13-0.35 mg·kg^-1, Cu 3.45-12.73 mg·kg^-1, Cr 0.21-0.37 mg·kg^-1, and Cd 0.05-0.12 mg·kg^-1.