Potholes in Edmonton: A closer look at 100 Avenue

Every Sunday for the last couple of months I have driven down 100 Avenue, so I know firsthand just how bad the potholes on that street are. Every week they seem to get worse, but not evenly across the street. Some places are far worse than others. It got me thinking – why are some areas of 100 Avenue so rough while others are smooth?

100 Avenue

I considered the section road from 170 Street east to 149 Street. Closer to 170 Street there definitely seem to be few, if any, potholes – for the most part the road is smooth. Right around 163 Street, the potholes get really bad. For a while there was a pothole big enough that I’d describe it as a crater! As you approach 149 Street there seem to be less, but still more than the section closest to 170 Street. Why aren’t there potholes along the entire route?

My first thought was that perhaps the traffic volumes are significantly different for each part of the street. Fortunately, the Open Data Catalogue contains average annual weekday traffic volumes for the period 2006-2011, so we can find out. Here’s the result:

Unfortunately there isn’t data for the part of the street closer to 149 Street, but I can’t think of a reason it would be much different (especially since there is nowhere to go but north or east once between 149 Street and 156 Street, more on that in a minute). So it doesn’t appear that traffic volumes would have had much of an impact on the number of potholes.

My next thought was around the maintenance of the street – maybe sections were repaved at different times. I asked the City of Edmonton on Twitter, and was very happy to receive a response:

That actually aligns really well with my empirical evidence! The newest section of road, from 163 Street to 170 Street, is in good shape. The oldest section of road, from 156 Street to 163 Street, is in really rough shape. And the middle-aged section, from 149 Street to 156 Street, is a bit better. Clearly there seems to be a connection between the age of the street and the number of potholes it contains, at least in this example.

Remember that crater I mentioned? It was located right around 161 Street. Here’s what it looked like on April 16, 2013:

100 Avenue

And here’s what it looked like in May 2012, courtesy of Google Street View:

Looks like this is one of those potholes the City patches every year! Given that the street hasn’t been repaved in nearly 20 years, perhaps it’s time?

There are a few other interesting things to note about 100 Avenue. If you haven’t driven down there in a while, take a gander on Google Street View. Here’s a quick summary:

  • From 170 Street to 163 Street, there are four lanes of one-way traffic (east). For most of this section, there are sidewalks and commercial property on either side of the street.
  • From 163 Street to 156 Street, there are two lanes heading east, one lane heading west, and one lane of parking on the north side. There is residential on either side of the street, with a sidewalk on the north and a sidewalk separated by a landscaped buffer strip on the south. Traffic is restricted from turning south.
  • From 156 Street to 149 Street, there are two lanes in either direction (though in some places the west-direction is down to one lane). There is residential on either side of the street (except for a few strip malls on the north), with a sidewalk on the north and a sidewalk separated by a landscaped buffer strip on the south. Traffic is restricted from turning south.

One of the things you’ll notice as you drive down the street is that all the potholes seem to be on the south lanes where traffic is going east. No doubt this is due in part to traffic volumes (there’s a lot less traffic heading west). But I have a hunch that there’s more to it than that. I think there are two key features that contribute to the potholes, especially for the section between 163 Street and 156 Street.

First, I think the lane of parking on the north prevents potholes from forming there. Remember that you need water and traffic to create potholes. Even if the water drains toward the sidewalk as expected, the parking lane prevents the vast majority of traffic from causing potholes. Second, I think the landscaped buffer on the south encourages more water pooling. With less sun to melt the snow, more soil to hold the moisture, and more traffic, it’s no wonder that more potholes appear there. It seems there is so much water, in fact, that it overwhelms the drains in the area.

100 Avenue

I read the consolidated 100 Avenue Planning Study, and discovered there were good reasons for that landscaped buffer strip:

A number of concerns have been identified with respect to the impact of the 100 Avenue roadway improvements on the neighbourhoods of Jasper Place and Glenwood. These include traffic noise, speeding, pedestrian safety, and the possibility of traffic shortcutting, north-south between 95 Avenueand 100 Avenue.

The Stony Plain Road/100 Avenue Facility Planning Study, approved by Council on January 8, 1985,  recommended that these problems be dealt with by the installation of pedestrian crossings, the closure of some local streets south of 100 Avenue, and the development of a landscaped buffer strip along  the south side of 100 Avenue.

The study did mention that the existing stormwater system was “inadequate” but I’m not sure if or when that was originally addressed. I’m sure the authors of the study weren’t thinking about the possible impact of the design on potholes, but we can see the effects today.

All of this just reaffirms to me the complexity of the problem! Solving the pothole problem will have an impact not just on the way we maintain streets, but how we design them too.

Potholes in Edmonton

Every year the City of Edmonton spends a few million dollars to fill a few hundred thousand potholes. Are potholes just a fact of life, or can we do something about them? I think the latter. It’s time for a more sophisticated and creative discussion about potholes in Edmonton!

Pothole
Pothole photo by More Bike Lanes Please

We hear the same thing every year. As spring approaches, dozens of stories are published about Edmonton’s pothole problem. We hear all about the freeze/thaw cycle of the winter and that’s why the potholes are bad. We hear that the City has crews out all the time fixing potholes, on average about 400,000 per year. We hear that a lot of money is being spent on the problem!

Here’s what Mayor Mandel said a few weeks ago:

“If you look at this winter — we’ve had freezing and thawing, freezing and thawing way more than any other year,” said Mandel, “and we have had a little more snow than normal. It creates havoc.”

“It’s not our intention to create a pothole … but it is a fact of life in our city,” said Mandel. “It will be there forever and we’ll never catch up.”

That sounds like a challenge!

I started digging into potholes, well figuratively anyway. I started with a series of questions, and then I just began researching. I went through old council minutes, I looked at City reports, I searched through old newspaper articles, etc. What was supposed to take a few hours turned into days! After a while I realized I had better stop and share what I had gathered, so that’s what you’ll find in this post.

Here’s a video for those of you in the TL;DR camp:

Here are some of the highlights of what I found:

  • Potholes form when water and traffic are present at the same time.
  • The City has filled more than 5.6 million potholes since 2000.
  • On average, the City fills about 433,000 potholes each year, with a budget of $3.5 million.
  • Annual pothole budgets have ranged from $1.5 million to $5.9 million since 1990, for a total of about $85 million (or $104 million adjusted for inflation).
  • Edmonton seems to fill twice as many potholes as any other large Canadian city.
  • The City maintains more than 4,600 kilometers of roads. The average quality of an arterial road is 6.1 out of 10, just below the industry standard. There is not enough funding in place to prevent this from falling.

There’s a lot more information in this PDF report that I’ve put together:

I put all of the data I gathered into an Excel document that you can download here. You’ll find some data in there that is incomplete – if you have the missing information, please let me know! If you use it to generate your own analysis, I’d love to learn from you so please share!

How can we solve the pothole problem in Edmonton? I don’t know. But doing the same thing over and over isn’t going to change anything either. Here are some ideas on how to make progress:

  1. Information is only useful if we can bring it together to turn it into knowledge. I’ve started to do some of that in the report above. In the absence of good data about weather patterns or traffic patterns, it’s easy to make assumptions. I feel as though I’ve only scratched the surface – there’s a lot more information that could be correlated to develop a better picture of the pothole problem.
  2. We need to make better use of the tools and expertise that we have in Edmonton. I’m thinking of tools like the Open Data Catalogue, for instance, and expertise like the transportation engineers and soil experts we have. Edmonton is one of the few cities that tracks the number of potholes filled, let alone makes that data available online, but we can do more! We also need to do a better job of harnessing the collective power of all Edmontonians for crowdsourcing ideas and data. Potholes don’t have to be just a transportation problem.
  3. There’s lots of interesting things happening elsewhere – Edmonton is not the only city that has to deal with potholes! What can we learn from others? There are self-heating roads, nanotechnology is being used to create crack-proof concrete, and all sorts of different polymers designed to make roads less brittle. How can we apply some of that knowledge?

What if we brought together engineers, scientists, designers, programmers, and other citizens for a one-day pothole unconference? What would they come up with? I think it’s an idea worth exploring.

Splash
Splash photo by Owen’s Law

I don’t think we’ll solve the pothole problem in Edmonton just by throwing more money at it, and we certainly won’t get anywhere with cheap gimmicks. Instead I think we need to get a bit more holistic and creative in our approach.

For now, I have two calls-to-action:

  1. If you’ve never reported a pothole using the City’s online form, give it a shot here. Don’t bother with forms or maps on other sites – use the official one.
  2. If you found anything in this post valuable, please share it with others.

Thanks for reading and happy pothole dodging!