The municipal government urged residents to take the metro this year to help reduce traffic and conserve energy as several key road construction projects get underway, officials said at a press conference Tuesday.

The projects include the elevated road above Hongmei Road South and the middle ring elevated road in Pudong New Area, according to the Shanghai Urban Construction and Communications Commission.

"In addition, many main roads and expressways in the city will undergo comprehensive safety inspections and maintenance in 2013, requiring them to temporarily close, further exacerbating the traffic problem," said Qin Yun, the commission's deputy director.

There were 549 road construction projects in progress at the end of 2012, 339 of which were located downtown, according to the municipal traffic police.

It will be difficult to ease traffic congestion because of the rapidly rising number of vehicles on city's roads, Qin said. Shanghai has 2.62 million registered vehicles as of last year, up 4.3 percent from 2011. Of the total, 1.40 million were registered by private car owners, an increase of almost 18 percent from 2011.

The subway will play an increasingly important role in the city's public transportation system, said Yang Xiaoxi, the deputy director of the Shanghai Municipal Transport and Port Authority.

New metro lines will open this year, which officials hope will help allay the traffic problems above ground. Qin said that metro lines 11 and 16, and part of Line 12 are scheduled to start running in 2013. The new lines are expected to increase the average metro traffic to 6.8 million rides a day. The subway system accounted for 36.5 percent of public transportation traffic last year, second to the city's bus system, which accounted for 45 percent of the total.

Officials touted the energy efficiency of the subway compared with other forms of public transportation.

The local transportation authority surveyed 10,000 households from all over the city to get the statistics.