By Candy Thomson, The Baltimore Sun
6:58 PM EDT, April 23, 2013
Most weekday mornings, late spring through late summer, Terry Weller and George Foster climb into a bright yellow truck and fire up lasers, high-definition cameras and a bank of digital recorders before hitting the road.
Weller and Foster are two of the state's pothole detectives. Their laboratory on wheels is a $1.3 million truthmobile from which asphalt cannot hide its faults.
Cracks, bumps and ruts lose their anonymity to ARAN — the Automatic Road Analyzer — a tool that finds trouble before it finds motorists' front tires and suspensions.
ARAN can detect cracks as small as 1 mm in width. "It picks up everything — road kills, trash, graffiti —everything," Foster said with a grin.
Repairing pavement is the State Highway Administration's largest construction program. Of the $560 million set aside for projects in fiscal year 2012, nearly $200 million went to filling 2.2 million holes and smoothing surfaces. During fiscal year 2010, with its back-to-back blizzards, crews were much busier, filling slightly more than 3 million potholes.
On Tuesday morning, Weller and Foster are sleuthing on the roads just south of BWI Marshall Airport. Weller is the wheelman, guiding the truck at 40 mph down the middle of the right-hand lane, the most traveled and the first to show signs of stress. Foster rides shotgun, a flat-screen monitor filling the space in front of the dashboard and a keyboard at his fingertips.
Foster calibrates the equipment and begins the inspection. Laser beams check the smoothness of the road surface while cameras shoot a 90-degree video of their route. Lasers and a camera pointed at the road behind the truck take note of the black spider web of repaired cracks.
Watching the road and the screen, Foster marks with the click of a key any features worthy of review. His notations are synchronized with a GPS system and an inertial guidance system similar to one used on missile targeting systems.
All of the data are recorded on hard drives, about a gigabyte of information a mile, and downloaded at the State Highway Administration. Engineers analyze road measurements and video to devise what they call a "pavement management system" to set road maintenance priorities.
"We have the ability to virtually drive down any road," said John Andrews, assistant chief of the SHA field exploration division. "ARAN can provide engineers with enough information to initiate action."
Potholes are more than an annoyance, said Chris Storms, a spokesman for AAA Mid-Atlantic.
"They're really a safety hazard," Stroms said. "You can lose control of your vehicle if you hit a pothole, possibly leading to a crash, and it's just as dangerous to swerve to avoid it."
Repairing tires and wheels and realigning a car damaged by potholes costs an average of $700, said Chris Duncan, a State Farm Insurance agent in Baltimore.
"You see potholes any time of the year, but especially in spring, when pavement weakens after multiple cycles of freezing and thawing. The asphalt weakens and breaks down," Duncan said.
The SHA inspects each of its roads that measures more than one mile in length every year. That's more than 10,000 miles. About every three years, it looks at short roads and some county roads, too.
It is work that used to be done less frequently by crews with clipboards in vans and on foot. Their boots-on-the ground evaluations were time-consuming and subjective.
ARAN "is not a human measurement or judgment process," Andrews said. "This is an instrument process, an objective measure of conditions."
The SHA's first ARAN truck, bought in 1995, has more than 318,000 miles on the odometer. A more sophisticated truck, purchased five years ago, has logged 127,000 miles.
But as the price of asphalt increased and the state's road maintenance budget decreased, the automatic system took on added value with its ability to warn state engineers before problems get bigger and more costly, Andrews said.
The SHA repairs roads three ways, said Charlie Gischlar, an agency spokesman.
In winter, crews use a cold patch, filling the hole and compressing the material with a tamper. Once temperatures warm above about 50 degrees, damaged sections of roadway are cut away and hot asphalt is used as fill. Finally, when simple patching is no longer effective, SHA will use a milling machine to strip off the top two inches of asphalt and lay down a new surface.
On Route 176, just south of the airport, Weller and Foster are finishing an inspection before lunch. The hardest part of the job is maintaining a straight line through traffic and anticipating the actions of discourteous motorists who cut them off or tailgate.
"They take a lot of your concentration," Weller acknowledged.
And the truck's $1.3 million price tag?
"That crosses your mind, too."
Tips to avoid pothole damage
Reduce distractions and choose roads you know.
Use well-lighted roads at night.
Slow down so you can make adjustments.
If you can't avoid a pothole, don't slam on the brakes. Damage is less when a vehicle rolls over a hole.
Afterward, inspect the tires and wheels for damage. If the car "pulls" or the steering shimmies, take it to a mechanic.
Source: State Farm Insurance
Copyright © 2014, The Baltimore Sun