Prof blames asphalt recipe for pothole problems


It’s that time of year, when the first brave motorcycle riders are nosing out on the streets, only to be confronted by sand drifts in the roadway, along with thousands of potholes.

The sand drifts will wash away in the rain or get swept up by road crews, but the potholes? Sometimes those stay with us for weeks, or, in the case of CMG’s new home province of New Brunswick, the potholes stick around for years. ‘Arris and I both have craters in the streets of our towns that we’ve given affectionate nicknames, as they’re familiar faces that re-appear every spring.

OK, maybe I made some of that up.

But for those riders who are frustrated by the never-ending conversion of our public streets to lunar landscapes, there’s hope. According to an article in the National Post, one professor thinks we can prolong the life of our asphalt with a simple recipe change.

See, roadworkers across our country answer our constant complaints about potholes by saying there’s nothing they can do – the ongoing freeze/thaw cycle our roads see every spring means cracked pavement fills with water, then splits apart into gaping craters.

According to Simon Hesp, an engineering professor at Queen’s University who’s studied asphalt for two decades, there’s more to the problem than a simple squabble with Mother Nature. Hesp says paving companies are using asphalt that’s mixed with motor oil. That’s supposed to make the asphalt able to handle a wider fluctuation in temperature, and in some warmer climates, that might work.

Hesp says that isn’t the case in the Great White North, though; he claims all this used motor oil that’s being dumped into asphalt is actually making it more brittle, and more likely to break up, creating the potholes that imperil riders everywhere.

His proposed solution is simple: Stop dumping used motor oil into asphalt, since he thinks its benefits are far outweighed by its disadvantages.

According to the Post, not everyone agrees with Hesp; they list Alexander Brown, technical director of the Ontario Hot Mix Producers Association as a disbeliever, along with Prof. Susan Tighe, an engineering professor from the University of Waterloo. On the other hand, Mark Campbell, construction manager for the city of Kingston, says his city has implemented Hesp’s ideas, and they seem to be happy with it.


  1. Re Marquez breaking “his leg”:that is to say, his tibia. He would not have been able to ride had he broken his tibia. As far as I know, he broke his fibula which also attaches to his ankle. It hurts like hell (I know) but with pain killers and a small cast you can still ride. Adrian

  2. They may not be totally responsible for potholes but the use of carbide studs and the incredible road wear that incurs as a result is certainly a pet peeve of mine here in New Brunswick. Many deaths can be attributed to hydroplaning over water filled gullies in the road as they are left to wear down 5 cm or more quite often. It doesn’t seem to be the tractor trailers (as so many say) as this excessive grooving is not seen where studs are banned like mostly south of the border. If only the studs could be totally outlawed and mandatory use of winter tires in season were to be legislated (to put all vehicles on an equal ‘footing’) it would certainly free up more money to be spent properly maintaining our highways.
    And oh yeah Rob—Sackville is the Pothole Capitol of Canada—-highway signs will be erected soon.

  3. Kingston has some of the worst pavement/potholes you’ll ever see in a civilized nation, so I’d take mr. Campbell’s recommendation with a large bagful of salt … so to speak.

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