I do have a question for those in Ontario or familiar with the highways. First of all, as someone from Indiana I can too attest to some of the madness with "downloading" highways as we have that going for us as well, it's just called decommissioning or something like that. So anyway, I was told by my father one time when he used to visit Canada that a friend there told him that the reason the 400-series highways begin with the number 4 was because they were 4-lane highways (at the time anyway.) Is there any truth to this or was 4 just a randomly selected number to begin the new freeway designations?
Firstly, only Ontario has 400 series highways.

The term "downloading" was a term I believe that was coined by the media which referred to passing the buck on maintenance on one issue to a lower level of government. I believe in the early 90s, the federal government did a fair amount of downloading of stuff they used to take care of to the provinces, this was done for much of the same reason why the Harris government in Ontario did downloading to the municipalities, to try to create a surplus. Similarly, the opposite, if the Gardiner were to become the part of the QEW (which will never happen) would be called "uploading".
I've heard that story about the 400 series highways as well, but I'm not sure if there's any truth to it.
I could be wrong about this, but the reason why the freeway segments of say 115, or 11 don't have 400 series numbers is because they are isolated from the rest of the network. Perhaps if 35/115 was a freeway for it's whole length then it may have a 400 series number as it wouldn't be isolated from the 401.
Hwy 417 until the late 90s was isolated from the 401, I understand that, but considering how it continues on as another freeway in Quebec was probably why it got a 400 series number and not simply signed as 17.