Approximately, 297,000 cars have been registered so far in 2015, which represents an average annual increase of 30,000 since 2009. This is reflected in the sharp rise in traffic jams. Another negative factor is that 77% of the total cars on the roads are more than ten years old; 19% are 4-9 years old. A report has been produced based on data from fourteen air monitoring points. This shows that the highest nitrogen dioxide pollution level is at the central crossroads, where traffic has congestion is particularly serious. Pollution is worst of all at the western crossroad in the 13th micro region.