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How MapQuest Works


MapQuest Errors

MapQuest reports that less than 1 percent of its users contact them for any reason at all, so either very few people are getting wrong directions, or very few people are reporting errors. Still, with the volume of data MapQuest has to manage and all of the different sources of that data, it's simply not possible for its maps and directions to be all right all the time. Every now and then, MapQuest says to go north on a one-way street that only runs south or to turn left when you really need to turn right. Some of the most common MapQuest errors include incorrectly positioned addresses (caused by geocoding estimates), unrecognized addresses and incorrect exit numbers for highways.

When MapQuest doesn't recognize an address, it's usually the result of a time delay in getting updated information into the MapQuest system. If your house is located on a street that was completed only last year, MapQuest may not know you exist yet. Street-level changes in a city can take years to get into MapQuest's database. First, the new road has to be "dedicated" by the city, which can happen days, months or years after it's finished and in use. Once it's dedicated, the U.S. Post Office officially recognizes it. Once the U.S. Post Office recognizes it, mapping companies (who supply MapQuest with its data) update their information at their next scheduled update. Then, MapQuest updates its own data with the new road at its own next scheduled update. It's a bit of a roundabout process.

Incorrect exit numbers for highways, while not a widespread problem on MapQuest, can be a big problem for MapQuest users. People living in several counties in Utah have been late for appointments for the last year or so. In 2004, the Utah Department of Transportation changed hundreds of mile post markers and exit signs along I-15, I-70 and I-80 to correct previous innaccuracies. The DOT informed MapQuest of the changes in December 2004, but since MapQuest gets its data from other sources, it can't implement the corrections until its data providers confirm the changes and then supply MapQuest with the new information. As a result, as of November 2005, MapQuest still has incorrect exit sign numbers for more than 80 highway exits in Utah.

MapQuest has links in its Help section that you can use to report a problem with driving directions or a map (see MapQuest Help). Once you submit a report, MapQuest can begin the process of fixing the error. MapQuest will report the error to its data providers, who will confirm it (typically using human beings who actually drive out to the location and check it with their own eyes), correct it and then supply the new, corrected information to MapQuest.

For more information on MapQuest.com and related topics, check out the links on the next page.


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