International travel is increasing at a rapid rate. In 2017, a record 1.4 billion tourists visited other countries last year and that number is expected to reach 1.8 billion by 2030.

This swelling number of globetrotters also means growing queues at passport control. The vast majority of people who are detained by border agents don’t present a threat, which slows down the already often lengthy process of crossing an international border. Border crossing agents have a tough job. They have to make hundreds of judgement-calls every hour about whether someone should be allowed to enter a country. With the looming threat of terrorist attacks, people trafficking and smuggling, there is a lot of pressure to get it right.

Although they may have some additional intelligence on their computer system, when border guards examine most travellers, they’re relying on their own hunches and experience. And for many border control officers, that experience may not amount to much – it’s a position with a high turnover rate; border guards in the US quit at double the rate of other law enforcement positions.

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Anyone who has been stopped from entering a country at immigration, even briefly, will know what an upsetting and stressful experience it can be. Staring into the hard eyes of a border guard as they examine your passport is always a nerve-wracking experience.

But there could soon be another, unseen border agent with a hand in these decisions – one that cannot be reasoned with or softened with a smile.