The authorities on Monday ordered half the number of government cars off Beijing roads to ease congestion, reduce emissions and save resources for a greener Olympics in August.

"The government wants to take the lead in guaranteeing smooth transport during the Games," Zhou Zhengyu, spokesman for the Beijing transport committee and its deputy director, said on Monday.

The latest ban lasts till July 19.

Vehicles on the Northern Third Ring Road at 5 pm in Beijing yesterday, the first day authorities ordered half the number of government cars off the capital's roads to ease congestion in the run-up to the Olympics in August. [Agencies]

The Beijing municipal government had said in a public announcement on Saturday that it planned to ban 30 percent of all government cars starting July 1.

But the State Council decided to have all central government departments hold back half of their cars from Monday, to help cut fuel consumption by 20 percent.

"This prompted the municipal government to change its plan, in line with the central government's energy-saving policy," an official with the municipal Party committee's news office said on Monday.

The exact number of cars that will be affected by yesterday's move is not yet available, but the figure and its effect on the capital's air quality and traffic will be made known to the public soon, Zhou said.

A number of taxi drivers said they have started benefiting from the ban.

Zhang Zhenwang, a Beijing cabbie in his 40s, said his colleagues all felt the improved traffic on Monday.

"I went for a regular company meeting this morning without getting stuck on the road," Zhang said.

"The Eastern Second Ring Road was, surprisingly, not congested. While the flow was slow, the vehicles were moving ahead, instead of being at the usual standstill."

Smooth traffic helped the cabbie earn more than 70 yuan ($10) in one hour, which was "unimaginable" before because he used to get stuck in gridlock for 40 or 50 minutes in the morning peak hours and was prevented from picking up passengers.

Many motorists like Zhang expect the benefits of clearer roads to be greater from July 20, when 70 percent of government cars will be banned from Beijing roads till Sept 20.

As the ban includes public service units such as schools, hospitals and State-owned firms in the capital, the total number of cars to be removed could hit 210,000, Zhou said.

Beijing also has plans for its 3.3 million private car owners to abide by an odd-and-even license plate rule that allows them to drive into the city only on alternate days, between July 20 and Sept 20.

Only public service vehicles such as buses and taxis, and diplomatic vehicles, are being exempted from the rule.

The move is expected to reduce traffic in the capital by more than one-third and add 4 million people to about 12 million commuters that use public transport in Beijing every day, officials said.

"We will add 2,000 buses, open three new metro lines, and extend their operation hours to cater for the increased demand," Zhou said.

A four-day trial of the traffic-easing scheme last year also found that the public transport system's efficiency rose by 20 percent during the period, Zhou said.