Meanwhile, subway lines 5, 10, the Olympic line and a 28-km light rail linking the downtown with the airport are all to be in operation before the Games. It will only take 16 minutes to travel from downtown to the airport by light rail, compared with the current one-hour trip by road.

Thirty-four special bus routes linking Games venues will operate during the event, and they'll be free to those who have Olympic tickets.

To avoid traffic jams, from July 20 to September 20, cars will operate under an alternate-day driving system for odd- and even-numbered license plates. That's expected to take about half of the capital's more than 3 million vehicles off the roads. A test last August found the measure extremely effective in ensuring smooth traffic.

Many private car owners have also begun to reduce driving as their own contribution to improve the environment.

"I leave the car at home at least one day a week," said one Beijinger, surnamed Zhang. "Going to work by subway can prevent jams and save resources."

SECURITY A PRIME FOCUS

Beijing has 150,000 security guards plus 290,000 volunteers doing patrols. During the event, there will be at least 80,000 guards who are directly assigned to the Games.

This week, the city will start to deploy security staff at hundreds of checkpoints on road entries to the city to prevent dangerous people or cargo from entering the Olympic host city, according to the municipal public security bureau.

The subway is also carrying out security checks.