On a business trip to Edmonton last year when I was returning to the airport the gps insisted we should go downtown. Luckily getting to the airport is not very complicated so we succeeded without the GPS but we determined later that it was sending us to the postal station that houses the post office box listed as the address for the airport.
I once followed the directions given by my GPS to a hotel in New London, CT. After the long drive I was in the endgame, circling a block until… it told me I was at the hotel.
But I was in the parking lot of the police station.
I had to call the hotel to straighten this out and they guided me over a block.
The fellow at the desk told me that everyone’s GPS sends them to the police station. He then made the dubious assertion that it was because of some transmitter that the cops had.
I regularly go to and from Connecticut, driving around NYC. It’s a four or five hour trip that I wouldn’t dare make without GPS.
Why? Because that’s how I’m going to find my way around some weird part of the Bronx when unexpected road work sends me on a detour right off the main highway.
They do mess up occasionally, but not enough to render them useless.
I love my GPS too. But it’s annoying when I try to use it in one particular area near here, because it wants me to take the quickest route, which unfortunately happens to be a restricted park road that isn’t even wide enough for anything bigger than a golf cart.
My favorite was driving down the Michigan Ave in Chicago looking up directions as we drove and his GPS unit told us we were not on a road. Yep one of the most recognizable roads in the country and the GPS had it’s coordinates off. We thought it was a fluke due to bad reception or whatever but later that day on the same stretch of road going the opposite way ‘you are not on a road’
I write software for navigation systems. It’s an extremely difficult problem. People naturally want the best possible routes but they also want very fast calculation results. Getting both takes lots of ingenuity. (There are well-known algorithms that easily find a perfect path but take many minutes to finish calculating on a real-world map of North America – that’s not acceptable to today’s consumer.)
I’ve been in the industry for more than 15 years and calculated routes have gotten better and better but are still not perfect by any means.
The main thing that would help the cases in this thread is better map data in these harsh rural areas. I know for a fact that this is being worked on.
I was driving on the Alaska Highway through The Yukon and on a regular basis my GPS was telling me to “Turn Right, 300m” and such.
Really? Turn right here? HERE? And just plow through the forest? Because there hasn’t been a crossroad for 40 miles, seeing that it’s, you know, the freaking Yukon.
I can understand how a complex urban environment might confuse a GPS, but The Yukon is basically a vast wilderness with a few highways strung across it.
To me, a GPS is great for telling you where you are but not so great at telling you how to get around.
The time lost to a handful of incidents caused by imperfect maps or confused signals is dwarfed by the amount of time saved by its automatic traffic re-routing.
Did you master the spectral wolf? 
The story I remember is from back in the late 90s when Mapquest was new. And still easily confused, like so many others, by the intricacies of Boston area driving. Someone at MIT found that Mapquest’s directions between two points in Charleston (I want to say MIT and Hahvahd, but that’s probably not the case.) were to take the Sumner Tunnel into Boston, futz around there for a few streets, then come back to Cambridge via the Callahan Tunnel. Anyone familiar with Boston or Cambridge can tell you that crossing the river unnecessarily is a bad idea.*
*Then there’s the school of thought that driving in the Boston Metro area is always a bad idea. MBTA all the way.
I will frequently use mapquest maps to get directions, the one where you can tweak which route you get by moving internal points. I know how to pick my way around NYC to avoid 95 through the damned city, but it is usually the endpoint of the drive I am looking for directions for. You can set it to avoid seasonal roads, and tweak for time or distance. Print the maps and directions, and have those on hand along with the GPS. mrAru hasn’t driven the metro NY/CT/NJ/PA region as much as I have, and is still a hardcopy map person. Though we still have a couple road atlasses as well =) I guess it is sort of belt, suspenders and a piece of twine in the pocket sort of thing =) SCA events can be in the most obscure locations…
GPS once directed me on a route between two rural towns that I was unfamiliar with. At first, I thought, “This is cool, I never knew about this shortcut”, then my GPS reception quit for no reason, I and didn’t know where I was. I drove around aimlessly for a while, until my reception resumed. I wasn’t really lost, as I knew generally where I was, but rural roads in New Hampshire can be quite twisty and counter-intuitive as far as just how to get from one place to another.
I would put the percentage at even higher than that. I get around much easier than before I had it. Since I’ve had the GPS unit I’ve had that one bad incident. Before that, having to drive around looking, and even getting lost, happened much more frequently.
Obviously you have to use your brain, realize that it’s a fallible machine programmed by fallible people, and use some sanity checks. People who end up in lakes after ignoring warning signs have to take at least part of the blame themselves. As do fools who are desperate for work but don’t bother to make a test run to the interview site the day before. :smack:
I should point out that my instance was in the Mainline area of the Philly suburbs. For those not familiar with it, it’s a wealthy developed area. Admittedly there are lots of trees and you have to be careful of deer in places but that’s due to large estates and not because it’s a harsh rural area. It’s well traveled (with rush hour traffic jams) and well mapped.
(And no, I do not live in the Mainline. I wish! I live in an area of the Philly burbs that’s pretty much the opposite of the Mainline.)
Can’t I just take my junk?
Charleston?
Yeah, going from MIT to Harvard Square by way of South Carolina is not such a good idea. 
I’ve had a GPS try to send me the wrong way down I-80 (as in going the wrong way down an onramp and driving against traffic) and off a bridge (although I think this was due to recent road construction that the GPS didn’t know about). You do have to be careful not to turn your brain off.
We were taking several carloads of Girl Scouts from Northern Virginia to Wildwood NJ. One of the moms had printed copies of the directions for everyone.
Another mom said “No thanks, I’ll use my GPS”.
I got to the hotel first, and phoned the others to get an idea of how much longer they’d be.
GPS mom said “um… a couple of hours”.
She was in Lewes, Delaware, waiting for the ferry.
For those unfamiliar with the area, the normal way would be to drive up around Baltimore, through Maryland and Delaware, and exit the highway just over the bridge into NJ. The ferry is a fun alternative, but not the shortest, time-wise.
More recently: I got a Droid X phone, with GPS. We used it on a recent vacation, and had it in navigator mode when heading toward a friend’s house. At the last minute, it changed the directions and instructed us to go a different direction at an exit, than the direction we’d expected to go. Then it had us take a U-turn.
A week or so later, it did the same thing (after first instructing us to exit the highway an exit earlier than we needed to).
Could be worse - if you start out in North America, you have to kayak across the Pacific.
Used to be, you could get directions from North America to Europe; that involved swimming across the Atlantic from a wharf in Boston. Their time estimate was totally off - no way could someone swim 3000 miles in a month.
Ha! Well, I did feel the blood chill in my veins . . .
The problem isn’t that it doesn’t pick the fastest route, the problem is it sometimes tells you to turn the wrong way down a one way street, or tells you to turn on a road when you are on a bridge above the road it is telling you to turn onto, or the road it tells you to turn onto is behind a fence, etc. Hopefully those bugs can be worked out over time, I have no idea how it works.
FWIW, mine is very handy and I wouldn’t go anywhere w/o it. But I’ve learned that when I am going somewhere important I need to print out maps just in case the GPS has issues.