A Comparative Study of the Effect of Performance of the Vehicle Inspection Centers in Air Pollution Reduction in Tehran Metropolis and Other Metropolises around the World

Air pollution caused by traffic, bad traffic situation and critical condition of shipping are two 
major issues in metropolises that have been emerged in recent years. Today, mobile sources 
of air pollution in the urban environment is the largest contributor in which programs and 
policies of the inspection and maintenance of vehicles cannot be separated from transport 
environmental issues. Tehran metropolis is the twenty-fifth most populous city, is reported in 
the list of polluted metropolises in the world in recent decates. It seems that a major problem 
in the metropolitan transportation is the plans on road network conditions, equipment and 
road traffic management didn’t remain stable and have not developed enough in line with the 
importance of car traffic and growing number of vehicles, and on the other hand, lack of an 
adequate public transport system and subway lines makes the problem more visible. This 
leads to traffic and road congestion at peak times in a metropolis like Tehran which has a 
direct impact on increasing air pollution in the city, especially at peak times of traffic which is 
between two thirty to four o’clock. Using lands without any plan and lack of convenient 
transportation plans resulted in the centralization and concentration of industrial and 
commercial activities, schools, hospitals in Tehran which has added to the problem of 
congestion and increasing traffic in Tehran. The results of this study shows the reduced 
number of reference of vehicles to inspection centers in Tehran metropolis in recent years. 
Non-performance and strict implementation of rules relating to technical inspection centers, 
and illegally obtaining technical examination papers, the 5-year duration of the technical 
examination and lack of people welcoming are the causes of the problems and difficulties for 
technical inspection centers for light and heavy vehicles. Following the successful plans of 
technical inspection centers and public transportation in other countries in controlling air 
pollution will be discussed.