Citation

O'Neill W, Harper E. Transp. Res. Rec. 1997; 1593: 55-63.

Copyright

(Copyright © 1997, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

10.3141/1593-08

PMID

unavailable

Abstract

Location translation allows the use of multiple spatial referencing methods within a geographic information system (GIS). Most GIS users are familiar with planar or spherical coordinates expressed as (x. y) pairs of numbers whose values reflect the map projection used. Coordinates are characterized as unique physical locations on the earth's surface. Transportation professionals have added many methods of referencing data that occur along lines. Linear referencing systems generally reflect a measure of distance from a known point. Common linear referencing methods are route-milepoint and route-reference post-offset. Street (postal) address systems also fall into the category of linear references. Linear referencing methods do not uniquely define locations on the earth's surface without additional information about the location of the line (or road) on the earth's surface. Although many of the off-the-shelf GIS systems allow conversion among a wide variety of planar or spherical referencing systems, few accommodate linear referencing systems, and none are capable of translating among linear referencing systems or between planar or spherical and linear systems. Some of the issues that arise in the development of location translation systems are discussed. A description of the data model and database requirements of the system designed for the Utah Department of Transportation is included. This location translation system was developed to facilitate crash reporting in urban areas, although there are numerous applications within transportation agencies.