Pedestrians cross the road in Zhongguancun, Beijing, during a smoggy day in December.[Photo/China Daily]

Questions about vehicle restrictions in Beijing have been brought up on the sidelines of this year's NPC and CPPCC sessions.

Beijing vice-Mayor Li Shixiang has addressed suggestions authorities may be considering full-time vehicle restrictions based on the odd-even license plate system, saying that such a restriction is only going to be rolled out on certian occasions.

"The car restrictions could be imposed in Beijing in two types of scenarios. One is when a big event is held in Beijing, and the other is extreme weather. We are still making revisions to the draft. The draft will be submitted to the experts for discussion when it's done. When the extreme weather comes, chances are we might pull the most polluting vehicles off the roads first, then probably move to ban private cars."

An odd-even license plate system for private vehicle use has been used in Beijing on a number of occasions to keep pollution levels down.

There have been growing calls for this system to be implemented full-time to keep traffic moving and to keep down pollution.

Meanwhile, officials have also revealed plans to create an extra 9-thousand new parking spaces in Beijing over the next 5-years to cope with the notoriously high cost of vehicle parking and available space.