Pothole relief on the way
| • | Graphic: How the pothole machine works |
By Scott Ishikawa
Transportation Writer
It may be one of the most dangerous, most thankless jobs: fixing potholes.
"People zooming by, swearing at you if they think you're slowing down traffic," said state highways worker Melvin Chun, who has patched roads for 26 years. "I wish drivers would be a little more patient with us."
To the relief of Chun and his colleagues, someone went and built a better road-patcher.
The state Department of Transportation recently bought a $156,000 pothole patcher machine that is not only supposed to reduce the number of people needed on a crew but make it safer for them and create a more durable asphalt patch. The machine should be on the road this fall.
The traditional way of patching potholes, with hot asphalt and shovels, can also be irritating for drivers dealing with the leftover gravel flying all over their hoods and windshields.
The Rosco RA-300 Patcher can be operated by one person rather than a crew of seven.
Transportation engineer George Abcede said the vehicle will make it safer for state road crews because they won't have to step out onto the road as often.
Oil and asphalt are stored in separate containers in the 17-ton vehicle.
The two are heated, mixed, then sprayed through a reinforced hose into the pothole.
"The temperature is supposed to be precise enough where the material just pours into the hole," Abcede said.
A fine layer of aggregate is then sprayed atop the material to hold it in place.
The truck operator, from the driver's seat, can shoot the asphalt into the pothole using a 15-foot-long arm that maneuvers the asphalt hose.
Chun, one of the state employees trained to operate the machine, said crews can get more work done because they can attack potholes all day with the material stored aboard.
Hot asphalt in the back of a dump truck is usually effective for a little over two hours before it becomes too hard and unusable.
"After a while, you lose that consistency in the oil that holds together the asphalt," Chun said.
The new kind of mix is supposed to reduce the amount of flying gravel and tar that hits fenders and windshields after a freshly repaired pothole is hit.
Although the patcher machine is operated by one person, Abcede said a crew of three will probably still go out.
The other two will drive "bumper" vehicles to protect the front and back of the pothole vehicle with flashing arrow signs to direct traffic around the machine.
Chun hopes the vehicle can make things a little safer for the road crews.
"We had a road maintenance supervisor who died in the early 1990s after he got hit by a passing truck," Chun said. "Another guy broke his leg when a tire rolled off a car and hit him."
Chun also bristles at comments that road maintenance crews have an easy job.
"We travel around the island five days a week fixing these potholes; it's endless to keep up," Chun said. "Traditionally, you redo the asphalt surface every five years because of wear-and-tear, but with so many cars on the highways, we do it every 3 1/2 years.
Finding a cure for the common cold, however, may come before someone discovers a permanent pothole-patching method, he says.
Even a pothole the size of a silver dollar can gradually expand as more tires tear up the gravel.
"It gets worse when the rain seeps into the pothole and dilutes the oil holding the asphalt together," he said. "That's when the patch begins to fall apart."
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Scott Ishikawa covers transportation issues. You can reach him at sishikawa@honoluluadvertiser.com or at 525-8070.
