may take the money into their own pocket. Expressway automatic toll collection system using RFID 1.The units in expressway automatic toll collection system The expressway automatic toll collection system comprises:a data acquisition unit,the management of traffic lanes,lane control machines and settlement network interface unit,owner-managed unit and checking system unit. Simply speaking,a vehicle enters the automatic toll signal region,the RF card will produce a pulse induction signal to start the RF system to transmit the vehicle data through the network to toll sub-centers;the toll sub-center will determine the data,which is gathered,is egitimate or not,then it will sent the calculated results through the network to toll management center;the toll management center will get the results by using the transmitted data and with the reference history information of the data,then it will sent the results to the toll station inverse;toll station will make the corresponding action based on the results. 2.The key technology in expressway automatic toll collection system 1)The recognition of moving vehicles:RF vehicle identification system can identify a long distance and a fast speed.Vehicle can be identified in a short time. Vehicle identification system is composed by the car radio cards and reading devices. RF technology is non-contact means of communication.RF card reader and RF card collect data through wireless communication and identify the characteristics of the carriers. 2)Data transmission:To ensure data transmission system's secure is the key to long-term work.Since the transmission of data of RF technology requires only a fraction of a second,the time period can be used is very short.Besides since it is microwave radiation and has a low frequency,the probability of being stolen is low. This ensures that the security of the data collection phase.In the process of the data sending to the center,the transmission line is used,it ensures data transmission security.may take the money into their own pocket. Expressway automatic toll collection system using RFID 1. The units in expressway automatic toll collection system The expressway automatic toll collection system comprises: a data acquisition unit, the management of traffic lanes, lane control machines and settlement network interface unit, owner-managed unit and checking system unit. Simply speaking, a vehicle enters the automatic toll signal region, the RF card will produce a pulse induction signal to start the RF system to transmit the vehicle data through the network to toll sub-centers; the toll sub-center will determine the data, which is gathered, is egitimate or not, then it will sent the calculated results through the network to toll management center; the toll management center will get the results by using the transmitted data and with the reference history information of the data, then it will sent the results to the toll station inverse; toll station will make the corresponding action based on the results. 2. The key technology in expressway automatic toll collection system 1) The recognition of moving vehicles: RF vehicle identification system can identify a long distance and a fast speed. Vehicle can be identified in a short time. Vehicle identification system is composed by the car radio cards and reading devices. RF technology is non-contact means of communication. RF card reader and RF card collect data through wireless communication and identify the characteristics of the carriers. 2) Data transmission: To ensure data transmission system’s secure is the key to long-term work. Since the transmission of data of RF technology requires only a fraction of a second, the time period can be used is very short. Besides since it is microwave radiation and has a low frequency, the probability of being stolen is low. This ensures that the security of the data collection phase. In the process of the data sending to the center, the transmission line is used, it ensures data transmission security