Agencies in Idaho, California and Colorado are using Automated Machine Guidance, 3-D modeling and Intelligent Traffic Control Devices.
In 2013, the most recent year surveyed, the Federal Highway Administration (FHA) found that 16 percent of the nation's highways were in poor or mediocre condition and needed repaving or larger repairs.
Agencies in three states are in the beginning stages of changing how large-scale road projects like these will someday be done and redone, moving away from traditional paper plans, onsite staking and employee-based monitoring to automate processes and enhance precision and safety with smart devices.
They're already seeing returns on investment — in the case of an Idaho pilot, saving one construction season and several hundreds of thousands of dollars, and in California and Colorado, working to keep employees safe, virtually monitor drivers and fully integrate GPS.
As traffic volumes have doubled in the area, the Idaho Transportation Department (ITD) has spent the last decade building seven new interchanges along 34 miles of Interstate 20 between Idaho Falls and Sugar City. The Thornton Interchange outside the town of Thornton is the last of these.
A so-called “diamond interchange,” it began construction in April 2016 and did away with the old I-20 intersection with 4700 South, the county road into Thornton. The project created an overpass for interstate drivers and realigned 4700 South, eliminating the existing four-way stop and making the area safer for drivers.
By piloting a new requirement in its bid advertisement — mandating contractors use GPS equipment on their construction equipment and Automated Machine Guidance (AMG) that would precisely follow required specifications — and releasing a 3-D model earlier than is typical, the state was able to virtually finish the $11.2 million project in October, roughly six months later.
Engineer Michael McKee told Government Technology that projects of this size typically require two construction seasons and are built from spring to fall in two calendar years. The Thornton Interchange was fully operational after just one construction season — and workers finished final details this spring.
Recognizing Innovation in Transportation
Two Idaho Transportation Department (ITD) road projects were recently named regional award winners at the annual conference of Western Association of State Highway and Transportation Officials (WASHTO), but innovations used in one build could transform the state’s use of technology in major builds.
The agency's cleanup of the Elk City landslide earned it recognition from WASHTO in the Operations Excellence category on Wednesday, June 28 in Juneau, Alaska, for the six-month, nearly $3.5 million cleanup of 47 million tons of mud, rock and debris unleashed on Highway 14.
ITD was also recognized for Best Use of Technology and Innovation for construction of the Thornton Interchange on Interstate 20 outside the town of Thornton in the eastern part of the state.
The 12 highest-scoring WASHTO projects from each region of the U.S. will compete for two top-winning $10,000 checks, each to be donated to charity or a scholarship of the state DOT’s choosing.
These winners will be announced at the American Association of State Highway and Transportation Officials’ annual meeting, in Phoenix, in September.
A quicker build saved the state at least $450,000 and could help forge new relationships between the state and its contractors, McKee told Government Technology. It also eased traffic congestion near Thornton, which is about 87 miles southwest of Yellowstone National Park, and crash reductions should help the project pay for itself quickly.
“Given that the estimated cost of a serious-injury crash is more than $600,000 and the economic cost of each fatality exceeds $2 million, it doesn’t take long for the new interchange to pay for itself in safety returns,” ITD Public Information Specialist Reed Hollinshead said via email, noting the estimated economic cost for crashes in Idaho in 2015 was $3.8 billion.
McKee said moving away from “slope staking” projects — designating elevations in writing on stakes pounded into actual construction sites — to GPS and AMG requirements is something the Federal Highway Administration (FHA) has been urging states to do in its Every Day Counts initiative, launched in 2009 to shorten project deliveries, “enhance roadway safety, reduce congestion and improve environmental sustainability.”
“They’re trying to make this happen because the equipment and the ability to make this happen has been around since 2004 to 2005,” McKee told Government Technology, referring to contractors’ use of GPS equipment and related technology.
But, McKee added, the FHA was “finding was [contractors] were putting these sensors on their equipment, but they had a hard time getting the departments of transportation to let go of 3-D models.”
Using AMG and releasing a detailed 3-D model eliminated the time-consuming slope-staking surveyors had traditionally done onsite before each layer of the roadway was laid, an Idaho official said.
“Providing the contractor with a 3-D model for the Thornton Interchange and requiring them to use automated grade control during construction shortened the required construction time,” ITD District 6 Engineering Manager Wade Allen said in a statement. “We reduced the impact to traffic by keeping two lanes open in each direction of travel through the busiest part of the summer.”
The project also used Bluetooth detection to enhance efficient traffic flow through the construction zone; and one 360-degree camera and three stationary cameras to monitor build progress.
McKee said ITD spent more time on this particular 3-D model; and, breaking with tradition, made it available to contractors who wanted to bid the project when the agency advertised it.
“A lot of times, if DOTs want to give up the model, they’ll do it after the bid has been awarded,” McKee said, noting a climate of mistrust is not unheard of between many DOTs and contractors, with the former afraid to release too much information about a project prior to awarding a bid.
“We spent a lot of time making sure the model was correct and so we felt confident we could give that model up at advertising,” he added.
This gave contractors, including the company eventually selected — Boise, Idaho-based Western Construction, Inc. — a clearer idea of what the project would entail.
California already uses 3-D modeling in developing major roadworks, and Caltrans surveyors use “a very highly advanced GPS” technology, John Liu, deputy district director, Caltrans District 6, Maintenance and Operations, told Government Technology.
Caltrans District 6 Senior Transportation Surveyor Scott Reinhart told Government Technology that some state road projects do use AMG — but he and District 6 Transportation Engineer Hector Trujillo agreed slope staking is still in practice, in part because there's no agencywide mandate for AMG.
Reinhart said one issue for the agency may be keeping 3-D models updated in a timely fashion, and making sure updates are pushed out to the contractor.
“For us, I think it just becomes an issue with knowing what works right now. I assume we’re close to running some kind of a pilot,” Trujillo said comparing the change in practice to the construction of traffic roundabouts — which were once rare in the state but are now increasingly common.
Amy Ford, a communications specialist for the Colorado Department of Transportation (CDOT), told Government Technology the agency has begun a pilot monitoring traffic in roadwork zones using Intelligent Traffic Control Devices, or I-Cones, to gather traffic information and monitor driver behavior.
Last week, CDOT also finished testing an autonomous vehicle that could save lives in construction areas: an "impact protection truck" similar to existing models that screen workers from out-of-control traffic but with one key difference — it’s driverless.
Ford said state officials believe CDOT and an agency in the United Kingdom are on track to be the first two to use this technology publicly.