The snow has cleared, but the work has just begun for Federal Way’s public works department.
Maintenance workers are now faced with the annual task of repairing potholes caused by the recent freezing temperatures.
A pothole, the deteriorated portion in a roadway, is the result of water seeping into the pavement. As temperatures cool to freezing at night, the water becomes ice and expands below the pavement, forcing the pavement to rise. As the weight of traffic continues to pound on this raised section — and the temperatures once again rise above freezing — a shallow divot forms under the surface and the pavement breaks, making a pothole.
Salt and sand used to melt snow and ice can also aid in the deterioration of roadways, said Marwan Salloum, street systems manager for Federal Way.
Salloum said the only way to prevent potholes is to have an excellent street system. Compared to surrounding cities, Federal Way is first-rate, he said.
“The city has one of the best roadway systems with a good budget,” Salloum said.
To ensure the preservation of Federal Way’s road system, an annual review is done to determine road conditions. The department uses the information to decide which streets need repairs or an asphalt overlay. An asphalt overlay involves the addition of another layer.
The typical residential road has a life-span of 15 to 20 years. An arterial, or main road, usually lasts for eight to 12 years, Salloum says.
Though winter has just begun, the public works department is already receiving reports of potholes in need of repair. The city does its best to make repairs as soon as possible. However, the cold weather prevents permanent repairs.
“We do a temporary repair with a cold mix,” Salloum said.
According to the Washington State Department of Transportation, permanent repairs made with hot asphalt can only be made in warm weather. These repairs are typically made during the summer months.
There are several steps to patching at pothole, according to WSDOT.
First, a layer of liquid asphalt, also known as tacking, is applied. The tack allows the hot mix of gravel and oil to bond to the existing pavement and takes about 15 minutes to cure, at which point a hot mix is applied. After the hot mix is applied, the area is smoothed and packed.
It is easier to patch cracks, buckles and small potholes when they are small instead of going to the expense of a full repaving.
To report a pothole, call (253) 835-2700.
Damage from studded snow tires
Cold weather isn’t the only thing causing damage to the roads — tires can cause their fair share.
Studded snow tires, which are often used in the winter to help with traction on icy roads, are actually very tough on the pavement.
The tires are only legal from Nov. 1 through March 31; any driver caught with the tires on longer than that could face a $124 fine.
Drivers should note that in areas where drivers are exposed to more of a wet road than an icy or glazed road, studded tires actually make stopping more difficult.
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Mirror reporter Kyra Low contributed to this report.
