We conducted a preliminary field study that examines the accumulation of Pb, Cd, Zn, Mn, and Cu in plants and soil along a roadway in Zion National Park. The study is designed to determine the effects of motor traffic on the accumulation of these heavy metals in various plant species and soil during 1 year and to determine if these accumulations decrease as you move away from the roadway. Preliminary results indicate that the amount of Pb, Cd, Zn, Mn, and Cu concentrations found are a function of the number of vehicles passing during a year and the distance from the roadway. Higher concentrations of these heavy metals are found in areas close to the road and in areas where traffic is moving slowly or even stopped. The heavy metal concentrations decreased as the distance from the roadway increased, and the speed of passing vehicles increased.