I'm nerding out here, but roads are complicated and it actually requires a qualifier! Assuming no exit-only lanes, there is a V-shaped area you can drive into:

I'm nerding out here, but roads are complicated and it actually requires a qualifier! Assuming no exit-only lanes, there is a V-shaped area you can drive into: the beginning of the new exit lane. And then it's followed by another V-shaped area that you can't: the resumption of the shoulder. One way you can tell the difference is lines, if they are painted properly. But you can also tell from context. If you know (from experience and/or road signs) that only one lane peels off for this exit, and if you have already seen the V-shaped area for the exit, then the next V-shaped area is not OK to drive into.