here is something to read . http://ijetae.com/f
Post# of 780
http://ijetae.com/files/Volume2Issue7/IJETAE_0712_47.pdf
now here is what ihsi has to offer in this field
Alternative Inductive Loop System
http://www.intelligenthighwaysolutions.com/te...-loop.html
ihsi smart parking solution
http://www.intelligenthighwaysolutions.com/te...-tech.html