Narrow roads often work better than wide ones

[MisterF]

^lol...that's just what I'm talking about.

This topic has come up before and I've never really been convinced about bothering to raise speed limits. For example, raising the speed limit on the 401 would just create more traffic congestion by increasing the variability between stop and go.

But now that you mention it, the 407 is the ideal candidate for a higher speed limit. By design, congestion is not an issue (if traffic starts slowing, they just raise the toll) and I'm sure the company wouldn't object to the idea (it would further increase the value of the service they provide).

Which gives me a thought: maybe highway tolls would get more public support if they were paired with speed limit increases.

And I have no clue how this relates to narrow roads.

I don't think people would drive faster as long as the police kept enforcing the speeds they enforce now. Photo radar would help too and I don't think anyone would oppose it if you could legally drive the speed people drive now anyway.

Design speed is determined by the Geological features of the road. Ontario picture you post a straight section of highway, there is no Geological features and thus design speed doesn't matter. Save for maybe MTO standards on ditches and shoulders.
It's pretty much standard in Ontario that all non-400 series roads are 80km/h speed limits.

Okay, maybe a better example would be this for Ontario and this for Wales. The Ontario one is built for at least 100 km/h but the speed limit is 80. The Wales one is built to a much lower standard - narrow right of way, no shoulders, sharper curves, poor visibility, few warning signs, and the centre line doesn't tell you if it's safe to pass. On roads like that the national speed limit is 60 mph, almost as fast as our freeways. But you don't have to go to Europe, in Canada other provinces and even parts of Ontario have higher speed limits than 80. Speed limits aren't a science, different jurisdictions post what they feel is appropriate.

I think the difference is that in other countries drivers are expected to decide for themselves what's safe and what's not. The design of the road dictates how fast you drive. In Ontario we expect signs to tell us what's safe and we don't have to think for ourselves as much. On that road in Wales the maximum speed is actually the maximum, while here it's treated more as a minimum.