Commuters have mixed response to new safety measures

SHANGHAI - With just over one month left before the Expo, security checks have been introduced on Shanghai's buses and subway lines, with over 500 X-ray machines and 3,000 safety inspectors guarding the city's public transportation system.

A pilot scheme launched earlier this year to install X-ray machines at 43 of the city's subway stations will now be expanded to all 280 stations. Regular safety checks will be carried out on buses and delivery trucks.

There will also be greater surveillance at the 40 million sq m of underground parking lots, shopping centers and other underground areas.