Hundreds of motorists have been stuck in a kilometre-long traffic jam at the WA border as grey nomads, backpackers, and families returning from holiday raced to get across before new border restrictions came into force.

Key points: WA Premier Mark McGowan announced strict new border restrictions on Sunday to combat the spread of coronavirus

WA Premier Mark McGowan announced strict new border restrictions on Sunday to combat the spread of coronavirus Penalties of up to $50,000 will be imposed in WA if people fail to self-isolate for 14 days

Penalties of up to $50,000 will be imposed in WA if people fail to self-isolate for 14 days The restrictions will not apply to essential services, including emergency services, freight transport or mining industry workers

Quarantine officials at the Eucla checkpoint, located along the 1,600-kilometre-long Eyre Highway, were swamped by travellers trying to beat the WA Government's 1:30pm lockdown.

People entering the state after the deadline are being forced to self-isolate for two weeks, although they are being allowed to travel home first.

After the 1:30pm deadline passed, the ABC watched as police took the details of drivers in six vehicles and waved them through the checkpoint.

Police take drivers' personal details at the WA border. ( ABC Goldfields: Jarrod Lucas )

WA's Health Minister Roger Cook said late arrivals would be tracked by the State Government.

"We will have police at each of the main arterial routes into the state and they will be screening vehicles as they come through," Mr Cook told ABC Perth.

"Where those vehicles are obviously freight or an essential supply they will be waived through and will continue to make sure that we can get important essential food and medicine into the state.

"If they are people who do not meet the essential services requirements they will be issued with a boarding card in a similar way that you fill out when you are coming into the country on a flight or a ship.

"They will be required to provide their details so we can track them as they self-isolate for 14 days."

Huge lines of motorists try to cross the WA border on the Nullarbor before the self-isolation rule begins. ( ABC News: Rhiannon Stevens )

Quarantine checkpoint swamped

In the 48 hours since Premier Mark McGowan declared "WA is at war" and announced tough new restrictions to combat the spread of coronavirus, traffic levels on the Nullarbor have spiked.

The Eucla Motel had to dip into its diesel reserves to ensure motorists could continue heading west along the Eyre Highway.

Quarantine officials at the Eucla checkpoint. ( ABC Goldfields: Jarrod Lucas )

According to quarantine officials, 406 vehicles crossed the border at the Eucla checkpoint on Sunday and 675 on Monday.

The average of the three previous Sundays was just 297 vehicles.

Most travellers the ABC spoke to were West Australians just trying to get home.

But to the bemusement of authorities on the ground, many people were interstate travellers who are continuing holidays they had planned before the outbreak.

Dane Parsons and Kayla Inglis were travelling from Byron Bay in NSW to stay with family in Perth "in case it all goes pear-shaped". ( ABC Goldfields: Jarrod Lucas )

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Victorian man Lindsey Bennett was among those who crossed before the deadline and said he planned to travel around WA for the next three months with friends.

"This virus going around. People are in panic mode," he said.

"It's over the top. Who knows who's got it?



"You're going to go into lockdown. What is that going to solve?

"The truck drivers are still going to go through. Who's to say they don't have it?"

Greg Pike ran out of petrol as he arrived at the Eucla checkpoint. ( ABC Goldfields: Jarrod Lucas )

Running on fumes

Perth man Geoff Pike and his partner Jae Baird drove more than 1,300 kilometres from Broken Hill and rolled into the Eucla quarantine checkpoint at 1:29pm on petrol fumes.

Their car was towing a caravan and stalled after running out of fuel.

"We ran out of fuel a few hundred yards down the road and suddenly we got a second wind so I just floored it," he said.

"We made it with a minute to spare … plenty of time.

"I am relieved I don't have to go into self-isolation."

The traffic jam at the WA border took more than six hours to clear. ( ABC Goldfields: Jarrod Lucas )

Motorists frustrated by lack of information

Heath Adams, from Fremantle, made it across the border in time after a marathon 24-hour drive from Victoria to Eucla.

He said the lack of information about the border closure had been frustrating.

"The information heading across the border was really unclear," he said.



"I've been looking for it online, I follow the Premier's tweets, and there hasn't been further information aside from you have to self-isolate after the border crossing.



"We don't know what that means, whether that meant when we got through the border we could pitch our tent for 14 days.

"We tried to organise a hotel here to put us up for 14 days, we didn't know if we'd have to drive back to my parents' house using fuel stations and interacting with the public on the way, it made no sense and it wasn't clear."

Retiree Ron Wirth and his wife Robyn estimate it will take them two weeks to get home to Brisbane. ( ABC Goldfields: Jarrod Lucas )

Traffic has been flowing in both directions, with Brisbane retiree Ron Wirth and his wife, Robyn, cutting short their dream holiday touring around WA in a caravan.

They were among the 75,000 people travelling around Australia using a caravan or RV as their home, according to Caravan Industry Association of Australia.

The association was encouraging caravan parks to set up registers of all visitors, in case contact tracing was needed.

"The rapid spread is incredible," Mr Wirth said.



"Who would have thought in our lifetime that we'd be scrambling to get home from one end of the country to the other? It's amazing."

Dutch couple Rob and Mary-Anne Heijnen are travelling around the country. ( ABC Goldfields: Jarrod Lucas )

Rob and Mary-Anne Heijnen, from the Netherlands, arrived Down Under for a year-long holiday on January 29 — just four days after Australia recorded its first case of coronavirus.



"We don't want to go home because in Holland it's worse with the coronavirus because it's a small country," Ms Heijnen said.

"It's more of risk than to stay here and it's more beautiful."

Outback motels, roadhouses hurting

The owners of the Eucla Motel, whose staff make up 16 out of the town's population of 45, were also facing an uncertain future.



Rasa Patupis, whose family has owned the business since 1967, said she would keep the motel open as long as possible to support her staff but admitted her clientele would disappear.



Backpackers Juliet van den Nieuwendijk, from the Netherlands, and Rodrigo Aravena, from Chile, were travelling across the Nullarbor to make connecting flights back home. ( ABC Goldfields: Jarrod Lucas )

Eyre Highway accommodation operator Fraser Range Station was in the same boat and temporarily closing.



Accommodation manager Adriana Verburg said most of the guests on Sunday had travelled to WA from the eastern states and were trying to quickly return home to avoid two weeks of isolation.



"For us it has been a little bit devastating, really, because you see that all your business is sort of disappearing," Ms Verburg said.



"As there will be no traffic going east or west, for us it's not possible to stay open.



"It is heartbreaking to close your business."



The border restrictions come just months after bushfires closed the Eyre Highway — the only sealed road linking Western Australia and South Australia — for 12 days in January.