Bumper-to-bumper traffic caused delays of up to an hour and queues stretching 18 kilometres on Monday afternoon, as thousands of Canberrans returned from an Easter weekend at the coast.
Authorities warned of significant delays, particularly on the Kings Highway, with many leaving their return trip home until the last moment.
Westbound traffic was queued about 17 kilometres on the Kings Highway at Braidwood at 2.30pm, prompting Live Traffic NSW to warn motorists to allow an hour for extra travelling time.
Drivers reported nose-to-tail traffic through Clyde Mountain right through to Braidwood and Bungendore.
Staff at the Braidwood Bakery – a popular stopping point for those headed to the coast – were "completely flat out" keeping up with this year's hordes of hungry holidaymakers.
"It's mad. To get across the street, you'd be silly to even try," a spokeswoman from the bakery said.
A car breakdown which closed one westbound lane about 2.15pm at Manar caused further pain for travellers, although a Traffic Management Centre spokeswoman said the congestion was less so than through Braidwood.
Heavy traffic on the Princes Highway at Batemans Bay added up to 20 minutes of travel time for northbound motorists at its peak, with queues of up to three kilometres.
Those heading north from Moruya also faced delays of about 15 minutes due to a queue of cars about 2.5 kilometres long.
Meanwhile traffic on the Princes Highway at Ulladulla was queued up to 11 kilometres, with Live Traffic NSW warning of delays of about 55 minutes at its height. By 2pm traffic queues had dwindled to six kilometres, with a half-hour delay.
Nowra and Berry experienced queues of about seven kilometres, with travellers warned to add 35 minutes to their estimated time of arrival.
By 5.30pm, motorists were told to expect delays of 45 minutes between Braidwood and Canberra with 8 kilometres of bumper-to-bumper traffic through the town around 5.30pm.
According to Live Traffic NSW, westbound cars were queued for close to 20 kilometres on the Kings Highway.
ACT chief police officer Rudi Lammers joined the chorus of authorities asking Canberra travellers to stay safe and alert on the roads.
Be patient, take your time, stay alert and stay safe as you travel home to Canberra this Easter Monday. Expect long delays on Kings Highway.— Rudi Lammers (@CPOACT) March 28, 2016
A spokesman from Queanbeyan Police expected the traffic to be "out of control" later in the evening and urged people to be patient on the roads.
NSW Police caught almost 1100 people speeding on Monday alone and have administered hundreds of thousands of breath tests across the long weekend.