Locating Equipment

This blog series Technology Highlight explores some of the ways that investments in innovation lead to better outcomes for infrastructure and public safety. When technology advances, it often becomes cheaper, more widely available and accessible, and helps facilitate faster, safer, and greener projects.

This series launched by highlighting the way that innovation leads to greater access to technology. Using mobile devices as an example, we saw the way that innovation drove prices down and quality up all while making a once exclusive technology virtually ubiquitous. From there, we dove into the damage prevention process and explored the way technology has taken One-Call centers from relying on paper records to seamlessly cross-referencing disparate records digitally on computers.

Taking the next step from the One-Call center, we explore the technology that pinpoints the underground infrastructure and allows locators and excavators to see what is below.

Once a locator receives a locate request, and after planning and prioritizing through their ticket management software, they arrive on site at the location of the proposed excavation. Upon reviewing the scene for physical signs of subsurface infrastructure and comparing with facility maps, then begin to locate.

Armed with locating equipment, they start with a hook up point if doing an active locate, or begin sweeping with the locator for a passive locate in which a signal is already present. In both circumstances, the locator uses a tool designed to detect electrical or magnetic fields. Much like a metal detector, these tools –often simply referred to as locators – sense the infrastructure below and ping for the locator. The combination of  transmitters, receivers, and digital display makes locator technology highly accurate.

Locating tools today are able to precisely measure facility size and width, depth, and the line it runs within inches of accuracy. Once successfully identifying the subsurface infrastructure, its depth, and its path, the locator uses color-coded spray paint to communicate to the excavator what is below.

The list of locator technologies is much longer than simple metal-detector-style wands. The federal agency tasked with monitoring and regulating damage prevention, the Pipeline and Hazardous Materials Safety Administration (PHMSA) in recent years released A Study on Improving Damage Prevention Technology. In it, they detail advancements in acoustic locating, ground penetrating radar, radio frequency identifying tags, tracer wires, marker balls, and more. These help locators detect everything from signal-producing wires to previously undetectable plastic pipelines. The series of Technology Reports from the Common Ground Alliance (CGA) similarly detail not only the staple technologies in the industry, but cutting edge innovation.

A simple YouTube search for utility locate tools reveals innovative designs and competitive products ranging in cost, effectiveness, and precision. This wealth of technology helps explain why excavation jobs that notify One-Call centers by calling 811 or entering an online ticket request avoid damage 99 percent of the time. First, by notifying utilities, the excavator is informed about which utilities may have subsurface infrastructure on site. Second, by utilizing high-precision locators, the specific type, size, and path of the utility lines can be designated on the surface with spray paint, flags, or stakes.

As technology improves and the damage prevention process is further refined, more and better information will be available to the excavator. Accurate depth measures are already possible with existing locator technology, but is not routinely passed along to the excavator. Similarly, digital photographs, sketches, enhanced ticket information, and virtual maps are not regularly made available to the people breaking ground with heavy machinery. Despite the technology existing to facilitate this communication and collaboration, there is still ground to gain.

In the next blog, we will explore this communication space and what information the utility operator, locator, and excavator can expect to receive during the damage prevention process.


Written by Benjamin Dierker, Director of Public Policy


Interested in other technology highlights? Stay tuned for more ways technology is making damage prevention safer.


The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization. An innovative think tank, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, energy, infrastructure, innovation, technology, and transportation.