  Nowadays, in developing countries including Iran, the number of vehicles is
increasing due to growing population. This has recently led to waste time
getting stuck in traffic, take more time for daily commute, and increase
accidents. So it is necessary to control traffic congestion by traffic police
officers, expand paths efficiently and choose the best way for decreasing the
traffic by citizens. Therefore, it is important to have the knowledge of
instant traffic in each lane. Todays, many traffic organization services such
as traffic police officer and urban traffic control system use traffic cameras,
inductive sensors, satellite images, radar sensors, ultrasonic technology and
radio-frequency identification (RFID) for urban traffic diagnosis. But this
method has some problems such as inefficiency in heavy traffic influenced by
condition of the air and inability to detect parallel traffic. Our method
suggested in this article detects traffic congestion based on IOT containing a
smart system that gives us traffic congestion by calculating the air pollution
amount in that area. According to conducted experiment, the results were
satisfied.
