WayLink Analyzes Pavement Distress

Pavement cracks under pressure just like people do.

But just like it’s better for humans to stop the stress before they crack, it’s important for pavement engineers to find and fix the small cracks before they cause a complete breakdown of the pavement infrastructure.

The hunt for tiny pavement cracks is usually done visually by people driving slowly up and down the streets. It’s time-consuming work.

But WayLink Systems Corp. of Fayetteville has a solution. The company has retrofitted a Ford van with a laser-based digital camera that can detect cracks in the pavement that are almost invisible to the human eye — cracks as small as 1 mm in width.

This Digital Highway Data Vehicle can monitor a 13.5-foot swath of pavement while going down the street at 60 mph.

WayLink isn’t the first company to use cameras to monitor cracks in the pavement from a vehicle, but it is the first company to use this particular laser-based digital technology.

Waylink is owned by Kelvin Wang, a civil engineering professor at the University of Arkansas who has researched pavement management systems since 1993.

Wang started developing ideas about how surveying roads could be done differently and more efficiently. He has received more than $1 million in grants to do research. What he came up with was the DHDV and the Automated Distress Analyzer.

By using WayLink’s latest technology and software, cities, states and airport commissions can save money by finding cracks before they deteriorate the roads. At the same time, they can cut labor costs associated with manually surveying the pavement.

“If the cracking progression in those areas is getting worse over time, then you need to watch out because those cracks can deteriorate to potholes and then that would lead to failure of the pavement,” Wang said. “So, you need some kind of prediction of how things would go.”

Fayetteville is the first city government to use WayLink’s newest technology to survey the streets, taking digital pictures and processing the data using its Automated Distress Analyzer.

The city of Fayetteville has budgeted $5.98 million for “in-house road pavements” over the next four years for city streets. That amount is roughly 13 percent of the overall budget, according to the city’s 2006-2010 Capital Improvement Program. The CIP states that $14.5 million, or 32 percent of the overall budget, is earmarked for street improvements. Transportation and street improvements make up roughly 70 percent of the city’s budget. So, it’s no wonder the city spent $70,000 last year for the latest state-of-the-art technology to take pictures and analyze the city streets.

Takin’ it to the Streets

In 1998, Wang started WayLink through the UA’s Genesis Technology Incubator. And in 1999, Wang and his group created the DHDV and the ADA.

The DHDV has gone through three rounds of technological upgrades. The first one had about 1,500 pounds of equipment, and the second round added line scanning that takes digital pictures of minute detail. This time around, the laser-based illumination digital photography was added.

While many other companies have the same type of vehicle to do surveying, Wang is the first with laser-based illumination, even though that product is available in the market. WayLink was also the first company to use digital photography to capture pavement images in the late ’90s.

But the ADA is what really puts WayLink ahead of the pack.

Inside the van, the seats — excluding the driver and passenger seats — were taken out and replaced with a swivel chair, desk, three computer screens and the Automated Distress Analyzer software. As the van travels over the pavement, two lasers on the back record images that are sent back to the computer and stored in the ADA database, Wang said. From that, a report is generated and given back to the customer with analyzed results. The report can help customers figure out how fast the crack progression is.

“It is very, very important for pavement engineers to know where the cracks are, what kind of cracks they are and how bad they are,” Wang said.

Customers can contract the DHDV or purchase it, he said. The van costs anywhere from $150,000 to $500,000, depending on what features are on it. Those features include — the Automated Distress Analyzer; high-resolution digital images for pavement surface and right-of-way; differential global positioning system; distance measurement; multimedia based highway information system; and a report writer, among others. (The decked out version weighs 6,000 pounds.)

Under Pressure

According to the U.S. Department of Transportation, highways in poor condition cost drivers 25 percent to 30 percent more per mile than highways in good condition because of wear and tear on vehicles.

Deterioration happens very quickly. Once that happens, it can cost several times more to fix it than if it was caught earlier, Wang said

States usually have to wait for federal funding before they can improve highways.

But by using WayLink’s technology, it provides the opportunity to cut costs by staying ahead of major problems. It also eliminates human error and labor hours surveying on foot. In Texas, there are 50 surveyors that work for the state’s department of transportation, Wang said. He said he’s not sure about how much money can be saved by using the DHDV and ADA over manually surveying.

The AHTD doesn’t use WayLink’s DHDV but has another one it uses to survey the roads. Wang said that his DHDV could cover every interstate highway in Arkansas in a few days and every Arkansas highway in a couple weeks.

In June, the Louisiana Department of Transportation and Development will receive its first Digital Highway Data Analyzer it purchased. It will be the first state department to purchase the product.

Fayetteville

Wang said it took a couple weeks to complete the survey of Fayetteville streets because of traffic congestion, slower speed limits and constant stops. Wang said the report hasn’t been finished yet, but the analysis saved the city time and money surveying the roads. Money the city saves is money taxpayers pay.

Terry Gulley, Fayetteville’s transportation manager, said the city usually does visual surveys in the slow months of winter. Five to 10 people will visually inspect the city streets from a truck in about a month using a rating form. Based on the rating form, the transportation department makes an assessment on which roads need repair or patchwork.

Once the city gets the data from WayLink, Gulley said the transportation department will do another visual survey to compare its findings to WayLink’s and then make a decision on whether or not to reuse the DHDV.

Gulley said the city does save money if it catches pavement problems early. “If we let it go, then it costs more,” he said. “If we catch it, then we can improve it with minimal dollars spent and get it back to first-class shape.”

The DHDV isn’t only for highways and city streets but also for airports. Last year WayLink was contracted to survey Atlanta Hartsfield International Airport’s runways twice to analyze its cracking progression. The same importance for safety and pre-empting deterioration for roads is also important for runways.

In October 2005, Denmark-based Dynatest International A/S inked an agreement with WayLink to exclusively market WayLink’s video imaging and ADA technology on the DHDV.

There are two DHDVs being used in China and one is being built for Dynatest Denmark. Fugro World Wide, based in the Netherlands, purchased a DHDV for its Texas location. Fugro purchased the first and second iterations of WayLink’s technology and is in talks to purchase the latest upgrade.

Fugro is an engineering consulting firm that supplies advice, technical applications and drilling operations by interpreting data and supplying consultation with technical support.