Understanding Potholes

Editorial: Seattle has some of the most dangerous road surfaces for riding a motorcycle on during the winter in all of North America

It's that time of year again. You know. First the rain, then a freeze, then the snow and before you know it—there's potholes on every block of any major street in the Northwest.

True?

Well, that all depends on two things. How a city maintains its roads throughout the year and whether they do effective pothole repair. Seattle scores a fat zero on both fronts, making it one of the most dangerous cities to ride a motorcycle in in North America during the winter months.

The above repair on this Seattle street has failed due to lack of tack sealing and crack filling when it was originally made and in the years since. It will soon be the next pothole on Seattle's Greenwood Avenue.

So here's what's going on: other cities, such as Shoreline, Washington, just to the north of Seattle, don't have nearly the volume of potholes because they take proper care of their streets. During non-winter months they use a process called crack filling to seal any cracks or fractures that have occurred in the road surface recently. Seattle used to do this, but has not applied the practice citywide annually in well over a decade.

When water penetrates the ground and freezes, it expands and causes the pavement above to rupture. When a large bus, semi, garbage truck or other heavy vehicle travels over the area, it causes the rupture to come apart and bingo, it's pothole time.

With proper tack sealing and crack filling the seams and cracks are less likely to allow water to penetrate under the pavement when it rains.

This section of 125th street will be sure to get the Pothole Rangers busy in the not too distant future. Proper tacking of this area would have limited how much of SDOT's proposed 9 million dollar 2012 budget they would have to spend for what will now become a huge repair project if not tacked.

A simple example of this is to drive Greenwood Avenue north from 90th Street North in Seattle to the city limit at 145th Street and note the extreme number of potholes and repaired potholes along the way. Also look for Tar Snakes, which are where the process of crack sealing was used to seal new cracks. You won't see many tar snakes, just the ones left over from days gone by, most of which have failed by now. Riding a motorcycle across this surface could be compared to riding through a field of land mines.

Now continue north, following the road to the right as it becomes Westminster Way. You have now entered the city of Shoreline. You'll note the number of potholes and pothole repairs diminish immensely and the number of visible tar snakes goes way up.

With Seattle pothole repairs, look for the use of tack sealing around the edges of each repair. You won't find any. The city's Pothole Rangers don't have time for that. They repair each pothole as quickly and ineffectively as they can and move on the the next one. The problem here is that without tacking the edges, the next time it rains, water enters the pavement and the edges begin to show wear, often within just a day or two of constant rain. What the Pothole Rangers repaired last week goes back on the list again for repair.

Above - Proper tacking procedures used in Shoreline on this potential pothole kept it from opening up after the recent Northwest freeze. The new crack in the lower right is nominal and will likely be tacked over this coming summer.

Is this efficient? Apparently Tom Rasmussen and Peter Hahn of the Seattle DOT and their managers seem to think so.

We don't.

In 2011, Seattle's Pothole Rangers repaired 25,110 potholes. The question is, how many of those were repeats based on not tacking in the first place? The 2012 budget for the current process is 9 million dollars. Can we tack and cut that budget by, say, 25%? Surely tacking now would allow for future budget cutting.

Above—Shoreline: A pothole that was filled several years ago was properly tacked around the edges and has resisted opening up as a result. The small fracture near the bottom likely won't worsen this year and will be tacked over in the summer.

As one road worker said—"There are three ways to fix a pothole. Quickly, cheaply and correctly, and each type of repair is done differently." There's no doubt, tacking adds extra time on and costs more money, but the payoff is not returning to the same pothole again and again. Is it cheaper to fix one pothole properly once, or to fix it again and again and again?

Above - Seattle: This pothole repair on Greenwood Avenue was less than 3 weeks old when it was photographed this winter. Because it was not tacked, it is already beginning to wear away and will go back on the list of holes to repair in the near future.

If you don't live in Seattle, take a ride around where you do live just to see how your city fares in proper street maintenance.

If you spot a pothole it's always a good idea to report it to the local road department. Seattle prides itself on having it's own phone number (684-ROAD (7623)) and email (684-Road@seattle.gov) to address pothole reports.

Above: The start of another pothole in Seattle, note the ancient crack sealing applied years ago but never maintained.

The city even has a live map online so you can see what potholes were recently repaired and which are up next. The sad thing is, those shown as repaired are a clue to where the next ones will be. At least until the current repair procedure changes ...

SR!/Winter '11

2016 Update: Since this article was first written, Seattle residents have voted-in several bond measures for street repairs. Greenwood Avenue was the recipient of some of that money getting repaved from 105th to 135th streets between 2013 and 2016. The city still does not have an annual crack sealing and pothole program that works, instead relying on their website-form to tell them where to go next, based on input from residents. That's not good enough as more miles of roadway are failing and the bond monies are now spent. Wherever you live, if you see a pothole, or crack, report it to your local Department of Transportation - SR!