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The concentrations of Zn, Cu, Cr, Ni ,Mn Pb, Cd, and V were determined in the plant species Chromolaena
odorata and soil samples along four heavy traffic density (HTD) roads with average daily traffic density (ATD) of
5,364 vehicles and one low traffic density (LTD) road of 1,358 vehicles per day in the metropolitan city of Akure
Ondo State, Nigeria. Soil and plant samples were collected at distances of 5m, 50m and 100m from the road. Metal
concentrations in plant samples were determined by UNICAM SOLA R32 Datta station V7. AAS model ,while
metal level in soil samples were quantized using Inductively Coupled Plasma – Emmission Spectrometry (ICPAES)
and Graphite Furnace Atomic absorption spectrophotometer (GFAAS). The mean concentrations followed the
order Zn > Pb > V > Ni > Cd for soil samples and Mn > Zn > Cu > Ni > Cd > Cr for plant samples respectively. The
result of analysis showed that metal concentration decreased with increasing distances away from the edge of the
road. The concentrations of these metals along the LTD were significantly lower than for the HTD. Further more
metal concentrations in soil and plant samples were related positively to traffic densities, with soil and vegetation
along the HTD having significantly higher (p>0.05) level of the investigated metals than those along the LTD road.
Keywords: Heavy metals, Low traffic density, High traffic density, Roadside soil, Plant samples.