TRAFFIC police on motorbikes with flashing sirens led a convoy of slick new black BMWs towards the Raffles City Convention Centre on Thursday night, drawing stares from curious onlookers.

It was a dry run in the run-up to the 13th Asean Summit and other related meetings which will get underway in Singapore on Sunday, and end on Nov 22.

Several stretches of roads in the the North Bridge Road and Empress Place area were closed from 6.30pm to 10pm on Thursday to allow the cops to make final test runs to ensure there are no hitches in getting delegates safely and smoothly to their meetings.

A gala dinner for the Asean Summit, to be held on Tuesday at the Raffles City Convention Centre, will see the stretch of North Bridge Road between Stamford Road and Middle Road and one of four lanes along Bras Basah Road closed for five hours from 6pm.

Some nearby lanes will also be closed for vehicle screening.

To facilitate a reception at the Asian Civilisation Museum on Wednesday, Old Parliament Lane and Empress Place will be closed from 2pm to 11pm, with several other roads leading there also shut down from 7pm.

There will also be vehicle checkpoints at the closed roads to prevent unauthorised vehicles from entering the area.

As traffic congestions are expected in the affected areas, signs have been put up at lamp posts and beamed from mobile electronic message boards advising motorists to plan their journey during the affected period and to factor in an extra 30 minutes in travelling time.

Roads leading to the Shangri-La Hotel, where the summit's meetings will be held, will not be closed but there will be spot checks on vehicles there.

Traffic police warn that morning and evening peak hour traffic there could be slow and motorists should start their journey early and avoid Anderson Road and Orange Grove Road where possible.

Only authorised vehicles are allowed into the closed roads during the road closures and police officers will be at hand to help direct motorists.

Affected bus services will be diverted and no vehicles will be allowed to park in lanes near the closed roads.

Vehicles found doing so or is seen as an obstruction will be towed away.