Using GSM technologies to collect and supply expressway traffic information

Traffic information collecting and distribution are necessary in intelligent transportation systems, which require two-way communications for cars to transmit and receive traffic information. The GSM network has an LCS function, and cell phones using AGPS technology could provide location with relatively high accuracy. Road traffic information, such as speed, rates of flow, density, and travel time, can be calculated using LCS parameters. China has full GSM/GPRS network coverage. The base stations along expressway have the capacity to transmit road traffic information. New GSM technologies such as NFC-SIM provide a road tolling method over air. China is at the beginning of ETC, so it is wise to incorporate GSM technologies into OBU in cars.