In July, Asvatha Babu and her husband set off for Bengaluru from Chennai to attend a wedding. Instead of taking their usual hatchback, owing to the amount of luggage they were carrying, they took an SUV, with their child seated in the back. The Chennai-Bengaluru expressway is partially operational, and there was a diversion on the way. Relying on Google Maps, the couple took a detour that would briefly take them into Andhra Pradesh. This was a common enough route to take — through Ranipet and Chittoor — for journeys terminating in North Bengaluru, while routes to the heart of the city usually rely on the highway network within Tamil Nadu itself.

In a few minutes though, Babu found herself on a “dirt road in the middle of nowhere with trees all around and basically no streetlights”. Two cars behind her were similarly stranded, a few kilometres from the Kunjanur Rainforest. Fortunately, there was enough daylight — and company — to backtrack and exit back north, and reach the Bengaluru-Tirupati highway, putting them back on track. But the detour had cost them precious hours, and by the time they reached the venue, the festivities had wound down.

Others have not been so lucky. Over the past year, numerous incidents have come to light where drivers navigating using Google Maps have found themselves similarly stranded, at odd hours. Early in December, a couple traveling from Bihar to Goa found themselves stranded in the Bhimgad Wildlife Sanctuary, and had to be rescued in the dead of night by Belagavi police. 

In the Budaun district of Uttar Pradesh in November, three people in a car died after taking an incomplete bridge amid dense fog and plunging off its edge into a river. There too, the Google Maps navigation had led the unsuspecting driver through a route that did not exist. In August, a car in Kerala’s Wayanad overturned into a stream following a walkway — suggested by Google Maps as a road — leading to three injuries.

Google Maps’s turn-by-turn navigation is massively popular around the world. In India alone, the tech giant said last December, 2.5 billion kilometres of navigation were requested by users per day. Google amasses map data from Indian cities and highways through a combination of commercial third-party sellers and user contributions. Roads, pedestrian walkways, expressways, buildings — these are all labelled by lane count, direction, permissible vehicle classes, and speed limits. Thanks to its massive user base and real-time data from these phones, Google is able to also use real-time data to provide travel duration estimates, and suggest alternate routes to avoid congestion.

But the real world does not always operate or change in ways that are immediately flagged by Google’s systems. For instance, when some of the northernmost stations of the yellow line of the Delhi Metro were shut this month (December), Google briefly misinterpreted the outage to mean that the entire yellow line was not functioning and provided much longer transit directions through buses and other metro lines that extended travel time, sometimes by over an hour. For experienced commuters heading to work in the national capital, this may not have been a problem. But data lapses in remote areas and highways can have more far-reaching consequences.

Traffic advocacy group SaveLIFE Foundation’s founder Piyush Tiwari placed the responsibility of traffic incidents like the one in Budaun squarely on local authorities. “The current news cycle about the involvement of GPS in the particular crash appears to be entirely based on an unscientific analysis of the crash, and hearsay, mostly in social media,” he said in an emailed statement. “Prima facie, it appears from the crash images as published in the media that the crash site was an unsafe, unguarded and untreated bridge construction zone. The liability of the fatal crash therefore falls entirely on the road-owning agency and the bridge contractor for failing to prevent the movement of vehicles on an incomplete bridge section.”

The bridge was removed from Google Maps shortly after the incident. A Google spokesperson did not comment on the individual incidents but said that the company took “user safety and information quality incredibly seriously,” and that while it strove to provide users with accurate guidance, this was a challenge, as the best route between any two places can change constantly due to things such as sudden weather changes. 

“Now, we’re adding two new weather-related alerts in India for low visibility areas due to fog and flooded roads,” Google announced in an October blog post. The app accepts contributions in real time from users on accidents and road closures. The Google spokesperson said that these reporting mechanisms were being simplified, and that in urban areas, the company was partnering with traffic police to get “authoritative” sources of information on traffic disruptions.

How does Google obtain road data in the first place, especially for unpaved ones or pedestrian walkways? Adhavan Sivaraj, a contributor to the volunteer-run OpenStreetMap (OSM) platform, pointed to the company’s use of satellite imagery, which is common across all sorts of mapping services. OSM allows contributors to mark various road attributes, like whether one is paved, number of lanes, and so on. Google Maps restricts the level to which individual users can contribute such data to the company, and their practices are not always open to scrutiny, Mr. Sivaraj says.

Using satellite imagery to add unpaved roads is also not a problem that can necessarily be detected immediately, as nearby expressways are likely always suggested as the best route. When there is a route closure, users are likely to discover the issue. A Google executive speculated — asking not to be identified — that another problem that was likely making issues worse was users selecting alternate routes while using turn-by-turn navigation, instead of following the recommended route, which is more likely to be safe and accurate.

“I think there is a lot of dependency on Google, on what it’s offering apparently out of its goodwill,” Mr. Sivaraj says. “There is so much dependency on something we cannot hold accountable. There is so much belief in just one map. And that is very dangerous.” There was little way for local communities to get involved in the representation of their own surroundings, he said.