Detailed study of Google Maps zoom levels

[hotdogPi]

Detailed map of Google Maps road levels from zoomed out to in. These levels have always existed, but some looked exactly like others.

Dead end: Dead ends, some exceptions.
White: Normal road.
Yellow: Road that used to be yellow (and is yellow in Google Mapmaker)
Route: Has a route number; there are some false negatives and false positives though.
Orange: Obviously light orange. Almost all US routes are at least this.
Thick orange: Used to look like a freeway, but looks like normal orange except in 2 specific zoom levels.
Freeway: Dark orange.

Zoom	Dead end	White	Yellow	Route	Orange	Thick orange	Freeway
5,6							Interstate only
7					Some shown, all US shown, gray	Some shown, all US shown, orange	Interstate and US only
8					Some shown, all US shown, thin orange	Some shown, all US shown, thick orange	Interstate and US only
9				Random	Some shown, all US shown	Some shown, all US shown	Random, all US and Interstate shown
10			Thin line	Shown	Shown	Shown	Shown
11,12		Shown	Shown	Shown	Shown	Shown	Shown
13,14	Shown, thinner line than white	Shown	Shown	Shown	Shown	Shown	Shown
15	Shown	Shown	Shown	Shown	Shown	Shown	Shown

Edit: Changed "are" to "and" once in the description.

[Alps]

So what happens when a road shows up on one zoom and disappears on the next one?

[hotdogPi]

So what happens when a road shows up on one zoom and disappears on the next one?

If you are talking about what NH 125 does (shown at zoom level 7 or more, but only partially at exactly 9), zoom level 9 is probably the worst zoom level out of all of them.