The 2010 Shanghai World Expo will adopt the odd-even system of number plates used in last year's Beijing Olympics to ease traffic congestion during the extravaganza.
Under the system, privately owned cars with odd and even number plates will be allowed on roads on alternative days in downtown areas on both sides of the Huangpu River.
The rule would be effective for at least the first week following the opening of World Expo on May 1, according to Thursday's Shanghai Daily.
With the six-month Expo expected to attract an average of 400,000 visitors every day, city officials said easing traffic pressure was a vital task, right up there with security.
Officials said the duration of the odd-even plate plan will depend on how it works initially.
"There will also be a great demand for parking places during the event," said Huang Rong, director of the Shanghai Urban and Rural Construction and Transport Commission, the local transport authority.
"We are now making all efforts to work out solutions to ease the problem."
Huang said the commission was holding talks with the city sports bureau to see if some downtown stadiums could offer free parking for some Expo visitors.
Meanwhile, with most of the Expo-related tunnel, Metro and road projects completed or due to open early next year, the traffic authority said it would conduct a two-week trial run, covering roads, trains and ferries, in areas around the Expo site beginning on April 14.
It said it would closely monitor traffic flow during the trial and ensure up to 400,000 visitors use the routes on some days.
Huang said all construction operations would be banned inside the central area of the city throughout the Expo period.
While this would mean a pleasing change in downtown areas disturbed by noise, dust and traffic jams, migrant workers may face reduced job opportunities after next May.
Huang said construction authorities would open projects in outer areas to create more vacancies for affected migrants.