
It has been mild and wet in Toronto over the last week, but normally at this time of the year, the entire city looks like as if it was just hit by some sort of apocalyptic chalk storm. Everything is white. And that's because we rely on rock salt and liquid salt brine to keep our roads and sidewalks free of snow and ice. Each winter, the city uses upwards of 130,000 tones of salt to maintain its service levels.
This is the tool of choice because it is both reasonably effective and cheap. However, the trade-off is that it does horrible things to the environment. It also ruins perfectly good shoes, which should tell you something about what it's doing to the environment. So it's a balancing act: Yeah, it's terrible for the environment, but we want usable roads and sidewalks. People slipping and falling is also a liability problem.
That said, when I was in Montreal over the weekend, I did notice a greater use of gravel:
