This piece is part of the Sidewalk Talk series “15 Innovations That Shaped the City.”
Global positioning system technology has found its way into our cities in myriad ways. GPS has, of course, changed how we get around, down to finding the nearest coffee shop. It is accelerating development of self-driving transportation and aids traffic light synchronization, even giving an early green light to a city bus that’s behind schedule. And it helps in the monitoring of natural disasters such as droughts, with scientists determining how much moisture is in the Earth just by measuring the signal’s bounce off the ground. “Scratch the surface of any urban system and you’ll find GPS playing some major or foundational role,” says Greg Milner, author of Pinpoint: How GPS Is Changing Technology, Culture and Our Minds.
Prior to GPS, military and commercial vessels relied on a system of satellites called Transit for navigation with accuracy in the range of tens of meters—not great. In 1957, a group of MIT scientists noticed that radio signals from the Russian satellite Sputnik increased and decreased depending on where it was in the sky. They also discovered that not only could they track a satellite from the ground, but a satellite could similarly track receivers on the ground. That led to a series of experiments by the U.S. military to track submarines: first-generation GPS.
The U.S. Department of Defense eventually launched a network of 24 satellites to enable highly accurate military navigation. But GPS turned out to be too big and too disruptive to stay confined to a government silo. When a Russian missile shot down a Korean airliner that went off course in 1983, President Ronald Reagan announced that the military GPS system would be free for all aviation purposes and anyone else. The DoD finally ceased purposeful limitations of public access, revealing true GPS navigation to be 10 times more accurate than what was available previously.
The 1990-1991 Gulf War put GPS on the world stage, when U.S. and allied troops used it to barnstorm across a featureless desert, catching Iraqi troops off guard and marking the biggest desert offensive in history. Demand quickly rose for commercial and civilian applications. Companies like Garmin and TomTom started making receivers for car navigation.
The major transformation came in the early 2000s, when GPS started showing up inside smartphones, creating a formidable technology tandem that set in motion many of the major trends in mobile technology. Tens of millions of people suddenly had smartphones in their pockets at all times, with a growing share of those devices carrying tiny GPS receivers that enabled an array of new map and navigation apps. Today, three-fourths of Americans use their phones for navigation and other location-based services, and soon the vast majority of the world’s population will be trackable in some fashion by satellites circling 12,000 miles overhead.
GPS integration into smartphones and cars didn’t just replace old road maps in the glove compartment; in the mid-2000s, it helped expand a nascent mobile-technology niche called location-based services. Google Maps, a navigation app launched in 2004, didn’t just help people get around downtown. It added new functions with each new layer of data, such as “Street View” images to connect people visually with their surroundings, and real-time traffic data to alert drivers to road congestion and suggest alternate routes. Waze, the navigation app acquired by Google in 2013, added another layer of intelligence—allowing drivers to report directly into the app not just accidents and hazards but police traps and road closures.
“That blue dot on the map is a huge thing, to have your bearings and easily explore a city,” says Milner. But the impacts go far beyond personal navigation. GPS also has transformed the way people in cities hail a taxi, find new romance, order food, or track a delivery, check-in with friends, and post photos of new spots or historic sites.
People have become so dependent, so quickly, on the utility of GPS services today that the cumulative effect is changing not just how we navigate cities but “may be altering the nature of human cognition,” writes Milner. Rather than tapping into on our innate spatial capabilities to direct us where we need to go, people end up outsourcing these mental tasks to their smartphones, potentially compromising their basic navigation skills.
Improved precision is the next great hurdle for GPS technology. Currently it suffers from a roughly 12-foot margin of error. Today that gap can be frustrating for people trying to hail a ride; in a future city filled with connected, self-driving vehicles, that limitation could have more damaging impacts. But progress is coming. In 2016, the European Union launched the first of 18 satellites in Galileo, a network that aspires toward accuracy of within three feet.
Security is another big challenge moving forward. One big solar storm could wipe out satellites and ultimately disrupt big chunks of infrastructure, many of which are embedded with GPS-based clocks. “A single GPS timing flaw,” Milner writes, “whether accidentally or maliciously installed, could bring down the electrical grid, hijack drones, or halt the world financial system.”
These hurdles notwithstanding, there’s no shortage of opportunities for GPS to help improve urban life. It can help organize self-driving vehicles, coordinate all transportation modes into a single system, give rise to richer models of the urban environment, guide access to underground delivery or waste bots, provide public space managers with feedback on usage and maintenance, tell firefighters who’s in a burning building — the sky, quite literally, is the limit.