During the construction of expressway

the natural vegetation and soil had been destroyed

soil quality has degraded. This paper takes an existing expressway road area soils as a case study

and give a summarization on the formation and characteristics of road area soils. This research results showed that in the degradation process of the soils

silt content

organic matter

available nutrient were gradually reduced but soil rigidity and pH rose. Worsening of the soil properties resulted from decreasing of silt and clay particles and organic matter caused the coarsing of soil particles. The pollution characteristics of heavy metals in soils of different function positions of road area were studied

and made an objective assessment of the pollution of heavy metals

which can offer an useful background material for subsequent research.