Very well done. Lotâ€™s a detail here, and it looks seemless. Clearly, it took a lot of time and effort.
I don't quite agree with some of your choices, however.
First, as this in-game map from SH1 shows, itâ€™s not Riverside that runs through the South Park area, but Bachman. You have Bachman going straight down from Old Silent Hill to connect with Sandford West of the river--the SH2 maps do have a road connecting there, but it isnâ€™t labeled Bachman.
At some point, Bachman and the river have to intersect (with a bridge), in order for Bachman to be on East side of the river, where it belongs in South Park. And rather than having Bachman turn East, I think the river has to turn West, because the above map suggests that Old Silent Hill is directly North of the Resort Area.
This, of course, throws a wrench in your attaching the Resort Area directly to the bottom of Central Silent Hill. The Origins map does have Riverside leading to South Park, but perhaps that should be the road running down the East side (which you've assumed is Acadia).
Basically, Old and Central SH, and the part of the river running between them, all need to shift East. The river should snake West between Old SH and the Resort Area and then turn South again towards the lake.
Secondlyâ€”and this is easier to correctâ€”is that Homecoming (and SH1, if you pay close attention) has Toluca Lake extending up into the East side of Central Silent Hill, where you have Midway Ave going off. Now, the Origins map does have Midway going off as an interstate, but it would have to either curve or bridge the lake.
Finally, Homecoming offers some revisions to the buildings themselves in Central Silent Hill, although they should be applied with discretion, giving precedence to the older games. Homecoming did fuck up much of Central Silent Hill, although I suppose the decades of time gone by allow for changes.
Here's what I would do:
Given the scale of your map, it actually fits quite well. Also, it makes sense that Toluca Ave should border the Lake.