GPS routing accuracy questioned

In a recent article “Emergency rescuers: Use GPS devices with caution,” the message was really about what happened to Craig Matthews, who turned off a major highway in northern New Mexico last spring, whose remains were found in July by his girlfriend and another friend. Why? Matthews had been traveling north on Interstate 25 when he talked to his girlfriend, Debra Hughes, who lived in Penrose, Colorado. When Matthews didn’t return home, Hughes called search and rescue. A state game warden found his truck lodged in a snowdrift four days later about 44 miles off a remote side road, U.S. 64. He was found approximately 4/10 of a mile from the vehicle.

Hughes thinks Matthews got confused after he stopped for coffee in the town of Raton which is on the Interstate, and got on 64 instead of the Interstate. She thinks he turned on his GPS to direct him toward home.

I’ve had an experience before with GPS that will tell you “This is another route to your destination,” and it takes you off on a dirt road, offering it as a shorter route than the one you had chosen. Hughes believes this is what happened to Matthews. This isn’t the first time someone has gotten lost using their GPS as their only navigation tool. The other day as we were returning from Colorado, this GPS issue became very clear to me. We were driving along supposedly the right direction on a main road, and then I saw a body of water. I knew we hadn’t passed by this recreation area on the way, and we had planned to retrace our route.

I had a tattered copy of a road map next to me and consulted it. Sure enough, it was a well known landmark, a recreation area that showed up clearly on the road map but not on the GPS on my iPhone. When I’d first consulted the road map on our way to our destination, my husband had laughed at me. “They don’t even sell paper maps anymore,” he said.

I replied, “Of course they do. Not everybody owns a GPS or a phone with one!”

I have been slow to give up paper maps, partly because I love maps and I love being able to spread them out in their entirety to see where I am in relationship to other places. But this incident showed me clearly that there was still a need for them. I think it is very easy to rely on spoken or visual directions from a device, that is not really showing you landmarks, or geography in time for you to make a wise decision as to what to do.

A less harrowing incident is outlined the following article published recently in the StarTribune Nation. Apparently, Google Maps and some GPS devices have been directing visitors away from Henry David Thoreau’s beautiful Walden Pond to another Walden – a reservoir that is not anywhere nearly so picturesque:

LYNN, MASS. – Walden Pond, Henry David Thoreau’s idyllic retreat in the woods near Concord, Mass., has long been one of the most famous day trips in New England, drawing droves of visitors seeking the tranquil beauty west of Boston immortalized in the 19th century philosopher’s writings.

But some 21st century conveniences — namely Google maps and some GPS devices — have been leading travelers to the wrong Walden: an identically named reservoir, next to a golf course, in this old industrial center on Massachusetts’ North Shore.

“I pulled up to that park and felt like I was in a county park — any old local county park,” said A.N. Devers, a writer from Brooklyn. Devers had entered the phrase “Walden Pond” into Google and cross-referenced directions on her iPhone.

As in more than a dozen tests on iPhones, Android phones and Google searches, she was pointed here, to a reservoir named for Edwin Walden, the president of this city’s water board in the late 1800s. “I do think I knew somewhere in the back of my head that Walden was near Concord,” Devers said. But like many wayfarers in a world increasingly reliant on GPS devices, “I just didn’t really process the directions.”

Google says it considers the user’s location, in part, to determine results — but a search from Cambridge, Mass., for example, returns Lynn’s reservoir, even though the Concord pond is closer. “It happens all the time,” said Dan Small, the ranger for Lynn Woods, where the reservoir is located.

The Lynn Walden Pond itself is a scenic place, although the lack of a cabin pretty quickly clues people in that something might be amiss. “We finally get there, and we’re like, is this it?” said Jeremy Corn, a restaurant beverage director who used his iPhone to navigate a trip to Walden Pond during his honeymoon road trip, inspired by his new wife’s love of Thoreau. When the two took a closer look at the map, they realized where they were — or rather, weren’t.

“At this point, my wife’s livid,” he recalled. “The Walden Pond thing was one of the only things she wanted to plan out, and we completely screwed it up.”

Ranger Small tries to break the news kindly. “I do it gently. I tell them that, ‘You know, it’s not the right Walden Pond, but apparently Thoreau was here at one time,” he said.

Thoreau does, in fact, refer to a visit to the area in a journal entry he made on April 26, 1859. It seems that he came here on purpose, guided by botanist Cyrus M. Tracy. “Walked with C.M. Tracy in the rain,” Thoreau wrote of his visit. “This is the last of the rains (spring rains!).” -StarTribune Nation, reprint from The New York Times

What to do? To me, these situations, both grave as well as aggravating, signal the need for volunteer geographic information (VGI) to help those third-party companies that provide map data to offer highly accurate data, to ensure the safety and accuracy of their maps. Until that happens, I suggest carrying your road maps in hand when traveling – and don’t let anyone tell you you are a Luddite!

Tags: geospatial, GIS, Google Maps, GPS, iPhones, navigation, volunteer geographic information

Category: Google

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