Most applications that use linear features can benefit from linear referencing. Example applications are outlined in the sections that follow.
Highways and streets
Agencies that manage highways and streets use linear referencing in a variety of ways in their day-to-day operations. For example, linear referencing is useful for the following:
- Assessing pavement conditions
- Maintaining, managing, and valuing assets—for example, traffic signs and signals, guard rails, toll booths, and loop detectors
- Organizing bridge management information
- Reviewing and coordinating construction projects
Linear referencing also facilitates the creation of a common database that traffic planners, traffic engineers, and public works analysts can use for cross-disciplinary decision support.
The following is an example displaying pavement conditions.
Linear referencing is a key component in transit applications, and it facilitates such activities as these:
- Route planning and analysis
- Automatic vehicle location and tracking
- Bus stop and facility inventory
- Rail system facility management
- Track, power, communications, and signal maintenance
- Accident reporting and analysis
- Demographic analysis and route restructuring
- Ridership analysis and reporting
- Transportation planning and modeling
The following shows the results of a corridor study, displaying the number of traffic accidents along a stretch of highway.
Railways use linear referencing to manage key information for rail operations, maintenance, asset management, and decision support systems. Linear referencing makes it possible, for example, to select a line and track and identify milepost locations for bridges and other obstructions that would prevent various types of freight movement along the route. Furthermore, linear referencing can be used to display track characteristics or view digital images of bridges and obstructions.
The following is an example of analyzing rail clearances along a rail line.
Oil and gas exploration
The petroleum industry manages tremendous volumes of data used in geophysical exploration. Seismic surveys, or shotpoint data, are used to help understand the underlying geology in an area. The nature of seismic data is that it must be represented as both a linear object—the seismic line—and a collection of point objects (the shotpoints). Both the seismic line and the individual shotpoints have attributes, must be maintained at the same time, and are used in modeling applications. Linear referencing helps solve this problem.
The following shows an example of posting and labeling seismic lines and shotpoints in the Gulf of Mexico.
In the pipeline industry, linear referencing is often referred to as stationing. Stationing allows any point along a pipeline to be uniquely identified. As such, stationing is useful in these applications:
- Collecting and storing information regarding pipeline facilities
- Inline and physical inspection histories
- Regulatory compliance information
- Risk assessment studies
- Work history events
- Geographic information, such as environmentally sensitive areas, political boundaries (for example, state and county), right-of-way boundaries, and various types of crossings
In the following illustration, pipeline coating material types are being examined.
In hydrology applications, linear referencing is often called river addressing. River addressing allows objects such as field monitoring stations—which collect information about water quality analysis, toxic release inventories, drinking water supplies, flow, and so on—to be located along a river or stream system. Furthermore, the measurement scheme used in river addressing allows the measurement of flow distance between any two points on a flow path.
In the illustration below, monitoring stations along a hydrology network are identified.