Groh tells his property manager clients that they need to keep two things in mind when considering pothole repair.
"The site conditions need to be examined and taken into consideration, and the expectations of repair should be reflective of the site conditions," Groh says. "The client needs to have a reasonable expectation for pothole repair, so he needs to understand how that repair fits into the surrounding pavement and how long the options he's considering can be expected to last."
The reasoning behind Groh's recommendation to his commercial clients is simple. To get the most bang from their pavement maintenance dollar property managers don't need a pothole patch that is in better shape than the surrounding pavement. So while they certainly need to repair a pothole, they might not want to repair it to the best degree possible.
"A lot depends on the condition of the site," Groh says. "A repeated temporary patch is often the best approach if the surrounding pavement isn't worth a greater repair investment. If that is the situation the contractor should point out to the owner that more extensive repairs are necessary when weather conditions allow."
Safety often dictates
In most repair instances the most important considerations for a property manager or city is the safety of the public, whether drivers or pedestrians, and the safety of the crew. Whether the pothole is on a parking lot or roadway, unrepaired potholes can lead to liability concerns from people swerving to avoid them, losing control of a vehicle after hitting them, or pedestrians stumbling into them. The more extensive the repair, the longer it takes to complete, the more the property or road is disrupted, and the longer the crew is exposed to the dangers of traffic. So most often the goal of the customer is simple: Get it fixed as soon and as quickly as possible.
The most common quick-fix pothole repair technique is generally considered the least effective, with the lowest up-front cost, and perhaps the highest long-term cost: the "throw-and-go" method. This approach uses a local cold mix asphalt thrown into a pothole, piled slightly above the surface.
Because it only involves dumping cold mix into a pothole, leaving the traffic to provide any compaction, this method is still used frequently because it's the most productive approach. Contractors and city crews can fill a large number of potholes in a day. But the mix doesn't last long in the hole. In fact, traffic often pulls the uncompacted mix out. The advantage of this process is the hole is filled quickly and the problem is solved, if only for a brief time, and crews are exposed only briefly to traffic dangers.
A slight improvement over the "throw-and-go" approach is "throw-and-roll," in which the cold patch is compacted and which FHWA studies say "should be considered a superior alternative to the throw-and-go method."
The high-performance option
A significant step above both those methods is use of specially designed high-performance proprietary pothole repair materials. These high-tech mixes, available in bags or in bulk from companies such as The EZ Street Company, Logan County Asphalt, QPR, and Unique Paving Materials Corp., combine aggregate and emulsion specially formulated to adhere to itself and to the pavement and also to resist the effects of moisture.
There are a variety of these types of products on the market, many of them specially formulated for the climate and aggregate available in a particular region, and they work much better than standard cold mix. Producers of the materials market them as "permanent" repairs, and tests have proved that when properly placed and compacted the materials often perform as advertised. However, they are more expensive than traditional cold mix, but the fact that they last longer means the life-cycle cost is lower.