Generating Electricity by utilizing Running traffic on Road

For this we can use piezoelectric transducers that have property to convert pressure or weight into electricity.Either we can introduced that sensors or transducers below road at the time of constructions or we can use peizoelectrical substances or particles at the time of construction or even we can add one layer of the material.We know that day by day population is increasing. Thus,traffic too.Now you can think how much volume we can generate electricity anywhere.