Linear referencing

Coordinates such as latitude and longitude are another member of the family, as are landmark references such as "5 km south of Ayers Rock."

Often, roads are created by engineers using CAD tools that have no geospatial reference at all, and LRS is the preferred method of defining data for linear features.

Another major drawback of linear referencing is that a modification in the alignment of a road (e.g. constructing a bypass around a town) changes the measurements that reference all downstream points.

In an era of mobile maps and GPS, this maintenance overhead for linear referencing systems challenges its long-term viability.

The US Federal Highway Administration is pushing states to move closer to standardization of LRS data with the ARNOLD requirement.

To wit: "On August 7, 2012, FHWA announced that the HPMS is expanding the requirement for State Departments of Transportation (DOTs) to submit their LRS to include all public roads.

Both systems are useful in different contexts, and while using latitude and longitude is becoming very popular due to the availability of practical and affordable devices for capturing and displaying global coordinate data, the use of LRS has widely been adopted for planning, engineering, and maintenance.

A station number written on a silt fence at a construction site