It's too bad they way they do runnels in this town, they always place them way over at one side, which means you have to kind of lean your bike out from the railing to make it work. I think for many wider or bulkier loads they won't work at all. I've seen other countries do it differently, making them wider, or even more centrally located on the staircase, but I assume in the rather staid and cautious approach of Canadian regulations and design that would be seen as creating risk for other stair users.
Here is an aftermarket (cheap looking design from BC, that at least pushes the channel a foot out from the railing:
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Here is another one (before/after) from Seattle that places the runnel to the outside of a railing making it basically a dedicated "lane" for cyclists, though if none were coming anyone else can use it, and have access to the railing. I think in standalone stairs like the Dundas Bridge this couldn't quite work as they need to be fenced in to prevent anyone from falling off the sides.
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Here is the ultimate: from Haarlem, NL (of course), showing two wide runnels, both located mid-width allowing both ascending and descending users to use whichever side they feel more comfortable with. And they both have sturdy edges to prevent the wheels from rolling off. The far left of this photo shows how someone who needed one hand on the railing and the other on the bike could potentially manage as well. With the toronto design, I don't think that is ever really possible, as the railing and runnel are both to the same side.
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Just for a comparison, here is the Wallace Ave pedestrian bridge off Dundas West, showing the super narrow runnel pushed up quite close to the railing (though it has a bit of room due to that ledge). It's also not useful for many wider tired bikes, unlike the Dutch and other options above that look like they could handle even some fat bike tires.
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