Integration of Spatial Point Features with Linear Referencing Methods

The Global Positioning System (GPS) offers a cost-effective and accurate method for inputting, updating, and analyzing spatial data. However, many data-storage and reporting methods at state departments of transportation and other transportation agencies rely on linear referencing methods (LRMs) for managing transportation data. Consequently, GPS data must be able to coexist with linear referencing systems (LRSs). Unfortunately, the two systems are fundamentally different in the way they collect, integrate, and manipulate data. For spatial data collected with GPS to be integrated into an LRS or shared among LRMs, several issues must be addressed. Various issues are discussed for integrating point features from a typical inventory system with an LRM or between LRMs, including two- or three-dimensional GPS to one-dimensional LRM, linear offset error, lateral offset error, matching to the wrong segment, and locating points between LRMs.