STEVE INSKEEP, host:
Ask anybody for directions and you'll see the strengths and weaknesses of the human species. People usually want to help, but the brain is not always so good with distances and street names.
Mr. JOHN MILLER(ph): I would say go down, like, E Street for a little while, and then I'd hook a left--or hook a right on--at Barnes & Noble.
INSKEEP: That's John Miller from Virginia who's bravely giving directions to a favorite bar in Washington, DC.
Mr. MILLER: ...little bit, there's like maybe four or five streets that come together, and so I'd take a left and go down...
INSKEEP: Miller says he often gets direction from a more precise source, MapQuest. Online direction services offered by MapQuest, Yahoo! and Google make getting lost a lot harder, but they're not perfect, not yet. NPR's David Kestenbaum reports.
DAVID KESTENBAUM reporting:
Jacob Sisk(ph) lives on a hill in Los Angeles, and it's one of those few places, one of those weird wormholes in the tangle of American asphalt, that the directions services screw up.
Mr. JACOB SISK (Los Angeles Resident): I had just moved a couple of years ago and I told a friend who was gonna come over and visit, see my new place, `Oh, just use MapQuest. Here's my address. I'll see you in a couple of hours.' And a couple of hours went by and I got an exasperated, panicked phone call saying, `None of the streets exist. I'm totally lost.' I said, `I don't understand. This doesn't make any sense. The Internet is never wrong. You must have done something wrong. Here, let me try and give you directions.'
KESTENBAUM: The MapQuest directions are great, for the most part. They give distances down to the 10th of a mile, they take you on a couple highways, get you close to his house, but then they say to make a right turn on Loma Vista Place. You'd put on your turn signal and realize that Loma Vista Place is a steep set of stairs.
Mr. SISK: Not even with the buffest of SUVs could you use this street.
KESTENBAUM: Sisk admits that he lives in a complicated part of the city, a maze of twisty little roads all alike. But if MapQuest can get you from the Grand Canyon to a pizza place in Queens, why can't it get you to Jacob Sisk's house?
Mr. CHRISTIAN DWYER (MapQuest): My name is Christian Dwyer. I'm the director of MapQuest.
KESTENBAUM: Dwyer says problems like this are very rare. MapQuest gives out about seven million sets of directions every day. Less than a 10th of 1 percent of those people contact the company at all, and he says only a fraction of those people complain about inaccuracies, though problems do happen.
Mr. DWYER: And here's a great example. A friend of mine was going from Marble, Colorado, to Crested Butte.
KESTENBAUM: MapQuest put his friend on a road that probably wasn't the best choice.
Mr. DWYER: It's not a paved road. It's a dirt road that goes up and over a mountain pass. It is the shortest distance to get you from Marble to Crested Butte, but it's not the optimum road to take your family sedan across.
KESTENBAUM: The way services like MapQuest work is they start with a database of roads, basically a digital atlas that lists roads, tells where they go and where they intersect. The Census Bureau puts one out for free, towns and counties have maps, and companies sell improved ones. But that's just the map. Eventually, a fancy computer program has to recommend some roads to get you where you're going. Jeremy Kreitler is senior product manager for Yahoo! Maps.
Mr. JEREMY KREITLER (Yahoo! Maps): So I'm now looking at the new Yahoo! Map site.
KESTENBAUM: I had him look up directions to Jacob Sisk's house on his computer.
Mr. KREITLER: OK.
KESTENBAUM: So could you tell me what's actually going on behind the scenes now as it tries to find your route?
Mr. KREITLER: Sure. So what happens is all of these roads, it knows about the connections between all of the roads there, but obviously there are a lot of different ways that it can get from point A to point B, and so what it does is on the sly, as quickly as it can, it explores all these different road connections.
KESTENBAUM: For a trip like this, he says, it may try hundreds of different routes. As math problems go, this one isn't actually too hard. An algorithm, a procedure for finding the quickest route between two places, was developed back in 1959 by a Dutch computer programmer named Edgar Dykstra. And route-finding software has become more sophisticated over the years.
Mr. KREITLER: You basically give it certain assumptions and you say, `stress using major highways more than minor roads,' or, `stress not having to take U-turns because those are really difficult maneuvers to do, try to make right turns a little bit more.'
KESTENBAUM: But when Yahoo! Maps spits out the final directions to Jacob Sisk's house, step 10 says `drive up Loma Vista Place,' which I tell Jeremy Kreitler is a staircase.
Mr. KREITLER: Oh, yeah. Well, that is--that is--it just goes to show that there are a lot of different complicated pieces to making this work.
KESTENBAUM: It turns out that MapQuest, Yahoo! Maps and Google Maps all send drivers up the stairs. The reason, apparently, is that they all buy a road database from the same company. They'd all get you lost.
Mr. KREITLER: Unfortunately, unlike a lot of services that are online, when Yahoo! Maps messes up, it really has a substantial impact to your life. You end up getting lost for a while. The nice thing is that it just shows how important these services are for people. But it does make it so that the service that you're delivering needs to be as accurate as possible.
KESTENBAUM: The road database company called NAVTEQ says the Loma Vista Place problem is being fixed. The company takes pains to make sure its information is accurate. NAVTEQ says it has over 500 employees who drive around in cars with computers to make sure the roads actually exist, but there are thousands and thousands of streets. David Kestenbaum, NPR News.
INSKEEP: So do you think you could find Jacob Sisk's house? Well, visit npr.org and you can check a Web map against pictures of his neighborhood.
This is MORNING EDITION from NPR News.