The statistics were revealed at a PSNI briefing on Tuesday, as part of an overview of an ongoing policing operation aimed at keeping people safe in the run-up to Christmas.
A series of attacks have been carried out by dissidents recently, including an attempt to bomb the car park of the Victoria Square Shopping Centre, close to Musgrave Street Police Station.
Letter bombs have been sent to senior officers and police patrols have been shot at.
Chief Superintendent Alan McCrum said 323 checkpoints have been mounted so far, with a total of 1,784 cars screened between 25 November and 10 December.
He explained: "Our vehicle checkpoints are much more sporadic (than during the Troubles) but it is also unpredictable.
"The checkpoints are much shorter in length but they also have a significant deterrent effect so we achieve a greater balance between public reassurance and protection."
In the most recent incidents, two separate police patrols came under fire in north Belfast and west Belfast - no-one was hurt but the attacks are being treated as attempted murder.
Assistant Chief Constable Will Kerr said: "There is a threat coming from dissident republican groups to the city centre and wider provincial towns.
"The only aim of terrorism is to cause disruption."
Police said they do not believe the extra security measures will disrupt the commercial life of the city during the festive shopping season.
Belfast traders are expecting a busy time for business.
Paul McMahon, of Belfast Chamber of Trade and Commerce, said: "All of the signs are that it is going to be a busy Christmas and we are open for business."
Colin Neill, chief executive of Pubs Of Ulster, added: "We are doing well, the recession has started to lift and we are starting to see that in the city."