Trust Your Eyes… Not Your Map

It happens in Minnesota. It happens in the maze-like city blocks of Manhattan. It happens in the deserts of Southern California, and the frozen wastes of Russia, and the mountains of Colorado. It happens everywhere, because we use it everywhere… perhaps, more than we should.

I’m talking about instances where your GPS leads you astray. Sometimes by taking you up a road that no longer exists, sometimes by thinking you’re on the freeway instead of the city streets, and sometimes by sending you into the middle of nowhere. At best, these incidents are inconvenient. At their worst, they cause “death by GPS.” 

There is a common misconception that these issues are completely due to user error. Occasionally, people point to the responsibility of the map-maker—these days, that’s usually Google. But rarely is it acknowledged that these incidents are a part of a wider group of human error that, while natural, should be monitored and corrected! 

Here, we delve into human-GPS error not in the context of specific stories, but as a wider phenomenon. We’ll explore the various kinds of human-GPS errors that are most common, and explain why they occur. Finally, we’ll make an argument for why and how to fix this problem.

From Traffic to Tragedy

Most attention on human-GPS errors is focused on “death by GPS.” These are deaths that are caused, in part, by someone following GPS directions. California’s Death Valley is, perhaps, the most famous location for these incidents and exemplifies its most common form: getting lost somewhere inhospitable. Ars Technica has a brilliant article on the subject if you want further reading. 

But, getting lost isn’t the only form of “death by GPS.” Far more common are car crashes caused by anything from stress over being lost, to going down the wrong side of the road. Not all crashes lead to deaths: some only cause injuries or property damage. These are rarely covered with the same attention, despite being more common.

When you investigate other incidents of GPS failure, the issue broadens. After a wash of people getting stuck on untraversable roads in 2021, the Colorado Department of Transportation had to issue a warning telling local drivers not to trust Google Maps. Sometimes, people go to the wrong place altogether. YouTube, meanwhile, is packed with videos of cars getting the tops sheared off of them due to mistaking the clearance they had available. 

In other words: while the deaths are obviously more tragic and eye-catching, GPS errors are a much more widespread issue than we might think. A study by Allen Yilun Lin, Kate Kuehl, Johannes Schoning, and Brent Hecht at Northwestern University analyzed 158 detailed news reports. While by no means a “broad” study, it does give us a good starting point. Aside from minor issues like trespassing, they included crashes (remarkably common), detours and wrong-destination events, getting stranded and stuck (occasionally in dangerous places), and driving down the wrong side of the road.

So, what causes these myriad issues?

Technological Causes

Once again, the study by Lin et al. is an excellent starting point for our purposes. Their report includes a table with the various technological causes of incidents within their analysis. 

They included, in ascending order of preponderance:

  • Missing/Incorrect geographic objects
  • Errors in translating location to coordinates
  • Coordinates that are similar, but incorrect
  • Poor instructions and visualizations
  • Lack of transparency and poor route choice
  • Missing or incorrect attributes, ranging from the physical characteristics of the road to traffic rules and clearance height

That last cause was, overwhelmingly, the most common, with 53% of incidents falling within that category. It is important to note that these aren’t the results of archaic GPS systems: this study was conducted in 2017. 

It may be hard for a modern audience to believe in this degree of technological error in something as omnipresent and supposedly reliable as our GPS systems, yet, in many of these incidents, the bulk of responsibility may be on the program, not the user, which begs the question of why these programs are so unreliable. 

Broadly speaking, it’s about the data available to your map, which is split between two issues: data about topology and roadways, and your GPS data.

The latter is not perfect. Aside from being sketchy, at best, at detecting direction, consumer GPS devices are only accurate to within about five meters. The US Interstate Highway standards call for lanes that are 3.7 meters wide, with narrower lanes used elsewhere. When the lanes are smaller than your margin of error, it’s impossible to get a solid reading.

As for the data about topology and roadways, not only is it absurdly difficult to manage—it probably shouldn’t be updated. At least not completely. Road conditions are always, always changing—a retrospective of your commute will tell you that. Keeping a map system entirely up to date in all respects would be a massive undertaking not worth the money and effort to implement all necessary systems. Informing users of all this data would drown them in notices that might be irrelevant. Besides, any solution would require giving even more data on ourselves and our cities to companies that have proven, time and time again, that they do not use it responsibly.

Still, some put the blame for human-GPS error incidents squarely on the user. Which, oddly enough, is an example of the same phenomenon that causes human-GPS error in the first place: automation bias.

The Human Cause: Automation Bias

One of the core causes behind human-GPS error is a long-standing, common issue:automation bias. It is a tendency in humans to favor results from automated decision-making systems to the point of ignoring contradictory information. From intensive care units to aircraft pilots, it has been a common issue in humans for some time now. The causes are myriad and up for debate. 

Human-GPS error is a form of automation bias. What separates it from other examples is that it involves something we use in everyday life, meaning that it’s going to be much more common. And, as mentioned, the criticism of drivers, in these incidents, is another example of the same phenomenon: instead of looking at the obvious errors of the tool, critics treat it as infallible and bash the driver.

There’s something in us—something that is arguably increasing—that wants answers and convenience. As a result, it’s willing to shift responsibility and cognitive effort for decision-making onto anything else that can take it… such as our maps.

Yet, in many of these cases, it’s logical to do this. We’ve been thoroughly taught that our technology knows better than us, and we’re most likely to use GPS systems in areas that we are unfamiliar with. As a result, our trust in our own judgment is already low: after all, what makes us think that we know this place we’ve never been better than a map explicitly designed for this purpose? 

Fixing the Problem: Trust Your Eyes, Not Your Map

Clearly, though, there’s a line here, somewhere. A sort of “margin of error” that we must accept in our GPS systems, account for, and correct with our own judgment. It’s finding that margin of error and knowing when and how to insert our own judgment that’s the hard part.

First of all, know that your GPS cannot be relied on for details such as road conditions and terrain. Instead, it focuses on basic facts: your point of departure, your destination, the shortest line drawn between one and the other, and the estimated time. In truth, it can’t offer you much more detail than a city map purchased at Barnes and Nobles. 

Second, use your GPS only as a guide but focus on your eyes. If you must, turn off the visual map and only use the audio alerts so that you can focus on what you see. This will ensure that you’re paying enough attention to notice things like road closures, warning signs, and detours. 

The key to knowing how to work with your GPS is knowing its limitations. Remember that it can only tell you what it thinks are the quickest routes from point A to point B. Despite all the flair, that isn’t as complex a task as it seems. When you acknowledge that the GPS is almost entirely ignorant of the details around it, you’ll be in a much better position to use it as a tool, instead of being guided by the nose.