In February 2008, the city-wide Low Emission Zone (LEZ) was implemented by Transport for London (TFL). Only trucks, taxis and buses fulfilling a specified emission standard are able to drive through this zone. To ensure effective control of vehicles, TFL has commissioned Siemens to install digital cameras for automatic license plate recognition at a total of 75 locations. The cameras record up to four million license plates every day. These are then transmitted in the form of encrypted digital certificates via an IP broadband network to a control center. On their arrival, the license plates are matched against a database and identified.