This document provides information about electronic toll collection (ETC) systems. It discusses how ETC allows for electronic payment of tolls using RFID tags to identify registered vehicles. It then summarizes the key components of an ETC system, including automatic vehicle identification, classification, transaction processing, and violation enforcement. The document reviews the specific ETC systems used at various toll plazas in India and discusses technologies like infrared sensors, RFID, and pressure sensors used for vehicle detection. Rate tables and operational details are also included for toll plazas on the Delhi-Gurgaon Expressway.