Traffic congestion has eased "obviously" in Beijing since authorities launched a string of new, stricter traffic rules and opened five new subway lines last month, a local transport official said Wednesday.

"On average, the duration of traffic jams has been reduced by more than two hours per day, from 3 hours and 55 minutes before the new year to the current 1 hour 45 minutes since Jan. 1," said Li Xiaosong, deputy director of the Beijing Municipal Committee of Communications.

Li's committee has unveiled an index system of Beijing's traffic congestion, the first for the city.

According to the system, 0-2 signified traffic was "smooth," 2-4 "generally smooth," 4-6 signalled "slight congestion," 6-8 "moderate congestion," and 8-10 "heavy congestion," Li said.

"Before the New Year, Beijing's congestion index usually stood above 8.2, but it has been 6 since Jan. 1," she said.

Li attributed the improvement to the new traffic rules and subway lines.

Massive traffic jams have long been a headache for Beijing, a city of 20 million people and 4.8 million vehicles. Last year, an average 2,000 new cars hit the city's streets every day.

On Dec. 23, authorities in Beijing announced they will slash new car registrations to ease traffic gridlock. This year, the city will allow only 240,000 vehicles to be registered, about a third of the number of last year.

Moreover, Beijing municipal government agencies and public institutions were prohibited from increasing the size of their vehicle fleets over the next five years.

Other measures include higher parking fees in the city's central areas, and stricter traffic rules for cars registered outside Beijing.