The traffic is the main source of air pollution in Georgia. The reason is the large number of vehicles (750,000 units registered in 1990), as well as the use of the low quality fuel and obsolescent car park.
In years 1992-1994 the fuel shortage caused considerable decrease in emission levels. Starting from 1995 the volumes of imported fuel was increasing as a result of private initiatives and hence the emission levels had been increasing either. Currently there is no fuel shortage but the quality of imported fuel is poor. Antidetonants like ethyl bromide, bichloride and tetraethyllead are used to compensate for the poor quality of fuel.
Since 1996 obligatory annual technical control of vehicles includes also the testing of exhaust gas quality. Drivers receive so called "toxic coupons" in case the hazardous substances do not exceed permitted levels. The "coupon" is valid for one year and allows the owner to test emissions of his/her vehicle once in a month free of charge.
The traffic air pollution problems are most serious in Tbilisi, Kutaisi and Rustavi. Tbilisi is in the worst position because the city with more then million population is located along the gorge of the river Mtkvari and natural ventilation is weak.