The mapping problems of the address to the latitude/longitude in an electronic map
1, UNITED PARCEL SERVICE OF AMERICA, INC.(UPS)，patent application(International Application No.:PCT/US2010/048562), such records:
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Transportation and logistics companies, such as UPS, license, purchase, and/or use digital maps from vendors like Tele Atlas® and NAVTEQ®. Companies receive digital maps that may include map data regarding streets, roads, avenues, bridges, highways, interstates, points of interest, geographic landmarks, and the like. A collection of navigable roads, streets, highways, and the like represented in a digital map are referred to herein as a "street network". Based on the street network, the map data of the digital map can be used to provide directions for traveling within a street network to a particular destination, such as to provide directions for traveling to a particular serviceable address to deliver a parcel.
As indicated, digital maps can be used to provide information for traveling, for example, from point A to point B. To do so, digital maps may include information such as street segments, altitude, longitude, latitude, speed limits, direction restrictions, and time penalties or other information associated with a street network or segments of a street network. For example, a street may be represented by a street name, an address range, and series of longitude and latitude coordinates that define the overall shape and location of the street. To determine directions for traveling from point A to point B, it should be noted that, in this example, (a) the digital map does not provide the precise location as to where a particular serviceable address is located on, for example, a given street, road, or avenue (e.g., it assumes a linear distribution of addresses on the given street, road, or avenue) and (b) it is assumed that both the start location of point A and the end location of point B are actually located on the street network of the digital map. For example, if a street is assigned an address range from 1 -100 and directions are needed to a serviceable address associated with the number 50 on the street, the map data is used to approximate where on the street the serviceable address associated with the number 50 is located. Using interpolation, for example, it will be determined that the serviceable address associated with the number 50 is located in the middle of the street segment as determined using the segment's length. So, for instance, if the segment is a mile long, it will be determined that serviceable address associated with the number 50 is ½ mile down the street segment as measured from the beginning of the street segment. In other words, the map data assumes a linear distribution of addresses in the street network and does not provide for precise location information regarding the individual addresses. Once used to provide approximate directions to a serviceable address, given the lack of information in the digital map, it also must be assumed that the serviceable address is located on the street network. For example, if a particular commercial building associated with a serviceable address is located on a driveway 2/10 of a mile off of the street network, the digital map data will not reflect this added driving distance and accordingly will not account for the specific connection location to the street network, added travel time, and travel distance.
In addition to the above-noted limitations of digital maps, digital maps may also contain errors that can even further exacerbate inaccuracies in, for example, routing applications used by transportation and logistics companies. For instance, digital maps may include street segments that do not exist and/or omit street segments that do exist. Similarly, digital maps often contain errors that include reversed high and low numbers for a street segment, reversed odd and even numbers for a street segment, and inaccurate high and low numbers for a street segment. Such errors often go unnoticed by most consumers because they can usually still arrive at their desired destinations even if the directions are inaccurate, such as requiring them to travel an extra 1/10 of mile longer on a street than was indicated. However, for transportation and logistics companies and other entities, such minor inaccuracies can lead to inefficient planning for parcel deliveries and non-optimized delivery routes.
2, Geocoding in wikipedia, such records:
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Example
Take for example: 742 Evergreen Terrace
Let's say that this segment (for instance, a block) of Evergreen Terrace runs from 700 to 799. Even-numbered addresses fall on the east side of Evergreen Terrace, with odd-numbered addresses on the west side of the street. 742 Evergreen Terrace would (probably) be located slightly less than halfway up the block, on the east side of the street. A point would be mapped at that location along the street, perhaps offset a distance to the east of the street centerline.
Complicating factors
However, this process is not always as straightforward as in this example.
Difficulties arise when
•distinguishing between ambiguous addresses such as 742 Evergreen Terrace and 742 W Evergreen Terrace.
•attempting to geocode new addresses for a street that is not yet added to the geographic information system database.
While there might be 742 Evergreen Terrace in Springfield, there might also be a 742 Evergreen Terrace in Shelbyville. Asking for the city name (and state, province, country, etc. as needed) can solve this problem. Boston, Massachusetts[1] has multiple "100 Washington Street" locations because several cities have been annexed without changing street names, thus requiring use of unique postal codes or district names for disambiguation.
Geocoding accuracy can be greatly improved by first utilizing good address verification practices. Address verification will confirm the existence of the address and will eliminate ambiguities. Once the valid address is determined, it is very easy to geocode and determine the latitude/longitude coordinates.
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A very common error is to believe the accuracy ratings of a given map's geocodable attributes. Such accuracy currently touted by most vendors has no bearing on an address being attributed to the correct segment, being attributed to the correct side of the segment, nor resulting in an accurate position along that correct segment. With the geocoding process used for U.S. Census TIGER datasets, 5-7.5% of the addresses may be allocated to a different census tract, while 50% of the geocoded points might be located to a different property parcel.[2]
The accuracy of geocoded data can also have a bearing on the quality of research that can be done using this data.
From: https://en.wikipedia.org/w/index.php?%20title=Geocoding&oldid=530166116