Major highways in NSW are choked with heavy traffic as long weekend holiday-makers return home to Sydney.

Vehicles were bumper to bumper on several major roads heading towards the city late on Monday afternoon, with motorists warned to be patient and allow plenty of extra travel time.

Holiday-makers are stuck in gridlock on the Hume Motorway, northbound, between Bargo and Wilton, as well as on The Great Western Highway, eastbound, between Mount Victoria and Blackheath.

Traffic jams are also reported on the M1 Princes Motorway and the Princes Highway northbound between Waterfall and Heathcote.

The Pacific Highway southbound at Hexham and the M1 Pacific Motorway southbound between Somersby and Mount White are also congested.

In its traffic report about 4.30pm, the Transport Management Centre also said Bells Line of Road, eastbound, approaching Bilpin and the Princes Highway, northbound, between South Nowra and Bomaderry are jammed.

Earlier, a three-car crash caused heavy delays on the NSW Central Coast on the M1 Pacific Motorway near Jolls Bridge, at Bar Point, just after 1.30pm.

Drivers have been urged to allow extra time to return to Sydney from regional parts of the state as heavy traffic trickles along major motorways.

“At the moment the advice is generally for motorists travelling home from the long weekend, allow plenty of extra travel time and plan ahead for delays,” Transport Management Centre spokesman Derek Peterson said.

Traffic in the city also caused headaches for thousands of Sydneysiders making their way to the beach for the public holiday as temperatures reached 30C.

Sydney beaches approached capacity, with swimmers turned away at Wattamolla and Garie beaches.