--FILE--Vehicles move slowly in a traffic jam on an elevated highway in Beijing, China, 23 February 2016. Beijing has preliminarily worked out policies on congestion charge for vehicles, reported National Business Daily on Friday (27 May 2016). Beijing Municipal Environmental Protection Bureau and Beijing Municipal Commission of Transport confirmed that research was conducted to test the policies on Thursday. The policy has been formulated on a base of the similar experience in Singapore, London and Stockholm. The congestion charge policy is to discourage the use of vehicles, especially in rush hour and congested traffic, for the purpose of easing the traffic and the environmental pollution due to excess gas emission. According to data, there are more than 5.6 million cars in Beijing and annual discharge of pollutants is about 700, 000 tons, said National Business Daily.