Early statistics are starting to trickle in on the effect of Canada-U.S. travel restrictions, allowing a first measure of the monumental impact on cross-border movement.

What the numbers show is a dramatic plunge not only for personal travel — but also for cargo travel.

That's despite the border still being open to cargo and several other types of travel: students, military, certain workers, and permanent residents are allowed to cross.

The preliminary data shows an 82 per cent drop in border crossings from the U.S. into Canada by land, and a 96 per cent plunge in arrivals on U.S. flights.

Those were the figures released Tuesday night by the Canada Border Services Agency (CBSA), showing travel for the week of March 23-29 compared to the same week a year earlier.

Data released by the Canada Border Services Agency on travel for last week, compared to the same week in 2019. (CBC News)

While commercial travel is still broadly permitted, it has nonetheless been walloped by the COVID-19 crisis. Auto production has seized up, for example, stalling the movement of parts between countries.

The CBSA figures show a 24 per cent drop in truck drivers entering Canada compared to the same week in 2019.

The statistics highlight the pandemic-induced effect on the economy and movement across borders.

Amid the mounting number of COVID-19 cases, the Canadian government placed border restrictions on foreign nationals on March 16 and then, in conjunction with the U.S., suspended non-essential travel across the border on March 21.

Restrictions applied differently at different crossings

The CBSA numbers extend beyond U.S. travel.

The agency said the volume of international air travellers into Canada was also down — by 92 per cent compared to the same week a year ago — while commercial air traffic sustained less damage, declining 16 per cent globally.

The language of the Canada-U.S. agreement allowing some travel is a bit vague.

It says permanent residents, students, military, cargo and essential workers can cross the border. But it also cites medical purposes as an example of essential travel — without elaborating further.

Canadian immigration lawyers who work with commercial travellers say cross-border movement has become extremely unpredictable; having a legal work visa is no guarantee.

Andrea Vaitzner says the rules are applied differently in different places.

For example, she said, U.S. customs officials at one New York border crossing are agreeing to process Canadians who hold TN and L-1 U.S. work visas; at another nearby New York crossing, U.S. officials are refusing those same visas.

As a result, she's advising commercial clients to avoid travel if they can, and most people are.

"Fewer and fewer Canadians are travelling to the U.S. for work unless it is to provide an essential service," said Vaitzner, a lawyer at Norton Rose Fulbright in Montreal.

"Companies that can continue operating [with workers working] remotely are continuing to do so."

Another immigration lawyer, Henry Chang, has provided the same advice: stay put unless it's absolutely necessary. That said, several of his clients have had to cross because waiting out the pandemic was not an option for them.

Chang, a partner at Dentons in Toronto, also reports visa-holders being treated differently at different U.S. checkpoints. He said he hopes for greater clarity on the rules soon from U.S. Customs and Border Protection.

"Some ports of entry continue to process [L-1 and TN visas] but others are sending them away until formal guidance is received [from Washington]," he said.

"In summary, there is a bit of inconsistency from port to port at the moment because there is no guidance for officers other than the [initial announcements in the U.S.] Federal Register notices."