In 2008, a Syrian truck driver was faithfully following his satellite navigation system and ended up 1,600 miles away from where he was supposed to be. He'd meant to go to Gibraltar, off the south coast of Spain. He arrived at Gibraltar Point, England, surrounded by a group of befuddled birdwatchers.

That's a pretty extreme blunder. But stories like this have gotten satellite expert Roger McKinlay thinking about whether we've become too dependent on GPS and other satellite navigation devices — particularly now that so many adults rely on their smartphones rather than their brains to get around unfamiliar territory.

For starters, these devices don't always work as well as we think they do, and can fail in surprising ways. That could become an even bigger problem as we push for driverless cars and other self-navigating vehicles. Worse, our reliance on GPS might be causing our innate navigational capabilities to atrophy over time, leaving us helpless when technology fails and we're forced to orient ourselves. "We've become overdependent," McKinlay says.

McKinlay, the former president of the Royal Institute of Navigation, recently wrote an essay for the journal Nature on how "automatic wayfinding is eroding [our] natural abilities." Curious, I called him up to talk more about the pitfalls of relying on GPS, what it's doing to our brains, and whether there are better alternatives.

Satellite navigation doesn't always work as well as we like to think

For most of us, 99.9 percent of the time, GPS works incredibly well. The Google Maps app on our smartphones gets us to where we need to go, and we don't think twice about it. But McKinlay is interested in those times that it fails. Because satellite navigation can go awry in rather unexpected ways.

The Global Positioning System (GPS) consists of 31 satellites orbiting Earth from 12,550 miles up, transmitting signals as they go. They were originally put up there by the Department of Defense to aid with military navigation, but can now be accessed freely by anyone in the world with a GPS receiver in their car or phone. The receiver just needs to pick up at least four signals to trilaterate your position.

There are a few kinks in this setup, however. For one, McKinlay notes, signals from these satellites are relatively faint, and can be bounced around by buildings or other structures, messing up the information gathered by GPS receivers. This is particularly a problem for downtown areas. "There are plenty of cases of drivers in built-up urban areas suddenly wishing they had a map," he says. (By the same token, GPS hardly works at all indoors — in those cases, your smartphone instead tries to pick up nearby wifi signals to "guess" where you are.)

Unreliable signals could become a much bigger issue if we try to fill the roads with self-driving cars, which are likely to rely heavily on GPS. After all, autonomous vehicles can't just work 99 percent of the time. They have to work 100 percent of the time. It's not okay for a driverless car to get bewildered for a bit because it's in a city center.

A second problem: devices that intentionally disrupt GPS are becoming more common, which is potentially a major danger for ships and planes.

"Back in 2009, engineers were testing a GPS system at Newark airport and kept encountering regular interference," McKinlay says. "They finally figured out, through closed-circuit cameras, that it was a passing truck driver who was using a GPS jammer so that his employer couldn't track him. There are also cases of criminals using jammers — which are handy for stealing cars — around ports, which can affect maritime navigation. This still isn't common, but it's being observed more often."

The US Coast Guard is increasingly worried about the effect of signal-jamming on ships, which are heavily dependent on satellite navigation. Officials have claimed that an East Coast US port (they didn't say which one) was paralyzed for seven hours in 2014 as a result of signal interference.

To be fair, countries are hard at work trying to fix these problems. Various US agencies have already augmented GPS with air- and ground-based systems such as WAAS and NDGPS to improve signal accuracy. Meanwhile, Europe is launching a network of 30 satellites, known as Galileo, to complement GPS. China is building up its own BeiDou system. These additional systems should bolster coverage, though they also cost a lot of money. (The US has invested over $10 billion into GPS to date, and spends about $1 billion a year to maintain the service.)

Combating jammers is a tougher challenge, and will either involve further ground-based augmentation or, in some cases, resorting to new technology. The Department of Defense is looking into eLORAN, a system that would complement GPS by sending unjammable signals from ground-based stations.

But even these fixes still leave another key problem with satellite-navigation systems: They'll only ever be as "smart" as the humans who direct them. The GPS that took the Syrian truck driver to Gibraltar Point instead of Gibraltar wasn't confused — the human was. And that's where McKinlay is particularly worried. Because in our growing reliance on GPS, we might well be losing basic navigation skills.

GPS may be ruining our ability to navigate for ourselves

Our brains have a pretty outstanding capacity for figuring out how to get around. London cab drivers manage to memorize more than 25,000 streets and can rapidly figure out the best way to get from Point A to Point B. Marshall Islanders can famously navigate vast tracts of open ocean without any instruments at all.

Neuroscientists have discovered that our brains have two different specialized systems for navigation. In one system, located in our hippocampus, we create spatial maps of the world around us, understanding how different streets and routes fit together. In the second, located in the caudate nucleus, we make a mental list of the different landmarks we encounter every day. Left out of the driveway. Right at the grocery store. Etc.

These systems can get better over time with practice. London cab drivers who acquire "The Knowledge" of the city's mind-boggling street network have been shown to have significantly larger hippocampi than the rest of us.

But conversely, as Joseph Stromberg has explained, there's some evidence that these systems can erode if they're not used. When we stop trying to figure out routes for ourselves and instead rely solely on the turn-by-turn directions of our GPS, our ability to work out spatial maps seems to get worse. "One Japanese study," Stromberg wrote, "found that compared with people who were given paper maps and figured out routes for themselves, GPS users later drew maps with less detail and accuracy."

McKinlay frets that this could lead to problems. Lack of navigational skills is how a Belgian bus driver could take 50 tourists 800 miles in the wrong direction because he punched in the wrong address on his GPS device. It means that when our mapping devices stumble, we're completely powerless. "You see increasing stories about people going hiking with their smartphones as their only guide," he says. "Then their phone dies and they're incapable of navigating for themselves" and have to be rescued.

"We think about the world around us completely differently if we've sat down with a map and thought about the best route before the trip," McKinlay argues. "It's way too optimistic to think we can just hand that task entirely over to our smartphone and it will be the same thing." (A grim example was this man in Spain who died after driving his car into a reservoir because his GPS didn't realize it was taking him down a defunct road.)

Even beyond navigational snafus, other researchers have wondered if our dependency on GPS is causing us to pay more attention to screens and lose connection to the world around us. "Instead of experiencing physical locations, you end up with a more abstract representation of the world," Cornell's Gilly Leshed told the Walrus.

As a remedy, McKinlay argues that schools should teach students map-reading and navigation as a critical life skill. He also suggests that researchers start looking at whether there are ways to design GPS systems so that they help us learn about our environment rather than making us unaware of the world around us. (It's unclear what exactly this would look like, but what if, as a default, these systems always walked us through the spatial map of where we were going? No doubt scientists would have to test whether this bolstered our navigational abilities.)

"Navigation is a real skill we have, it's something very fundamental and something we’re really really good at," McKinlay argues. "And we should be thinking about how to augment those skills with computers — not just trying to overwrite them."

Further reading: Is GPS ruining our ability to navigate for ourselves?

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