As per the scheme dubbed Air Pollution Control, each vehicle can enter a "restricted zone" in central Tehran for free for a maximum 20 days each season (three months), or 80 days a year, Mohsen Pourseyyed-Aqaei told Tasnim News Agency.
Spread over 88.5 square kilometers in central Tehran, the zone is bounded by Imam Ali Expressway in the east, Navvab Expressway and Chamran Highway to the west, Besat Expressway in the south and Hemmat Expressway in the north.
"Vehicles are barred from entering the area between 6:30 a.m. and 7 p.m. on all days, except for Fridays and national holidays. On Thursdays, the time limit is between 6:30 a.m. and 1 p.m.," Financial Tribune quoted Pourseyyed-Aqaei as saying.
"If motorists wish to enter the zone more than the number of times mentioned in the plan, they need to pay a toll fee."
The official said that the new scheme substitutes the odd-even rule introduced in 2005. According to the odd-even rule, cars could enter the restricted zone on alternate days, depending on the odd and even numbers of license plates.
Besides the new scheme, two other initiatives are currently underway in the capital to help curb the smog and ease the pervasive traffic congestions.
Tehran Municipality had launched the Air Pollution Reduction scheme last November to help improve air quality. Based on the plan, old and dilapidated vehicles were banned in the city and violators received a fine.
The other so-called "Traffic Scheme” is enforced in an area limited by Motahari Street in the north, Shariati Street (east), Kargar (west) and Shoosh (south) where cars, except for public transportation vehicles, are barred from entering the area between 6 a.m. and 7 p.m. It costs up to 414,000 rials ($3) for privately- owned vehicles to enter the zone.