Big US cities have had mobile license plate readers for a while: https://chicago.cbslocal.com/2018/02/13/cpd-license-plate-readers/ https://chicago.cbslocal.co

Big US cities have had mobile license plate readers for a while: https://chicago.cbslocal.com/2018/02/13/cpd-license-plate-readers/ https://chicago.cbslocal.com/2018/02/13/cpd-license-plate-re... Just not coordinated at the national level yet. It would be pretty expensive given the size of the country, the number of police vehicles involved, and the current cost per vehicle.