Idaho expands use of WIM/AVI technology at Ports of Entry


New weigh-in-motion/automatic vehicle identification (WIM/AVI) technology recently installed in southeastern Idaho at the Inkom Port of Entry (POE) is expected to fast-track benefits for commercial vehicles using the scales, the general motoring public, and local economies to the tune of US$2.1m annually.

Approximately 3,100 commercial vehicles use the port each day, and another 14,000 passenger vehicles pass by on Interstate 15. The estimated annual savings to the industry is based on time and fuel savings. The Idaho Transportation Department (ITD) says the motoring public will also see less congestion in the area of the weigh station, because fewer trucks will be required to pull in for processing. The WIM/AVI system allows commercial trucks that meet state size and weight limits to bypass weigh stations at highway speeds. It is estimated that 50-60% of commercial truck traffic will be able to bypass the port.

Loops embedded in the roadway track the movement of each vehicle through the system, which registers the vehicle’s weight and axle configuration as it travels over the scales at highway speed. As truck drivers cruise down the highway, the electronic system verifies that the truck’s legal weight, height, length, safety rating and credentials are in adherence with the law. If everything checks out legally, the truck driver receives a green light on their transponder or a message on a changeable message sign directing them to bypass the weigh station and continue on its route. Conversely, if there are any legal issues, the driver receives a red light or direction to report to the weigh station for further inspection. Drivers may also receive a red light for a random pull-in.

The system allows more time to be spent checking commercial vehicles for weight and safety violations. Trucks running safe and legal loads benefit by not being slowed down with redundant stops as they make their way across country. Economically, more freight moved more efficiently means better profit margins for the industries affected. The installation south of Pocatello finished in late January. A grant from the Federal Motor Carrier Safety Administration (FMCSA) kick-started the project. ITD’s part of the match was US$596,000 for building slabs and conduit runs to support scale installation and hardware for the WIM system. The project was fast-tracked from project design phase to construction due to extremely tight grant deadlines.

Canadian company International Road Dynamics Inc (IRD) supplied and installed the WIM and electronic pre-clearance system, and will maintain the equipment, software, and database for the next two years. Similar systems have been installed at the East Boise, Huetter, and Lewiston POEs. The Sage Junction POE is slated for the next WIM/AVI installation, starting later this year. The WIM/AVI locations are determined by factors such as volume of commercial truck traffic, need, and industry input.

“The possibilities are exciting,” said David Hankla, who manages ITD Ports of Entry in eastern and southeastern Idaho. “The system has been fine-tuned compared to earlier installations, so the potential upside is tremendous.”

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Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).