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The holy grail of street paving

Last weekend I went by Sidewalk Toronto’s “experimental workspace” at 307 Lake Shore Blvd East. It is open to the public every Sunday from 11am to 5pm if you’d like to drop in.

This week they had their #BuildingRaincoat on display, which is an adjustable awning system designed to protect public sidewalks, mitigate the impacts of adverse weather, and improve outdoor comfort.

Also installed were a number of the paving systems that they are currently piloting. They’re working with over 20 different vendors to try and create the “holy grail” of street paving.

They define that as a system capable of the following four key features: modularity, heating, lighting, and permeability. Here’s an example of what one of them looked like (it was snowing at the time and, yes, Doc Martens):

With modularity, the goal is to make it possible for a single person to be able to pull up and replace one of the hexagonal slabs. This would dramatically change how we repair and patch our roads. Supposedly, they’re also more resistant to cracks, which means fewer potholes.

The key benefit of a heated paving system is an obvious one. When needed, their test system automatically heats the slabs to 2-4 degrees celsius in order to melt any snow and/or ice. That’s as warm as you need apparently.

They have two heating systems running at 307. The first is hydronic (fluid in pipes just below the pavement) and the second is conductive heating (thin conductive film in or under the pavement).

I’m sure many of you will be questioning the environmental and carbon impact of a heated public realm. And that is certainly a good question. But the status quo in this city involves about 131,000 tons of road salts per year. That’s a problem.

The lighting feature is pretty neat because there are a variety of different use cases beyond just demarcating space. One example that Sidewalk gives is that it could be used in a bike lane to tell you how fast you need to ride in order to hit all green lights.

Finally, permeability matters because it minimizes runoff and allows water to be absorbed in situ. The tradeoff is that it makes the slabs structurally weaker. So that is still being worked on.

I am thrilled to see this sort of urban innovation taking place right here in the city. If you haven’t already, I recommend checking out 307.

2 Comments

  1. Tbone

    were these pavers also high albedo? Would be great to have something that didn’t add to the urban heat island effect.

    Like

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