I don't think so, no.
I could be wrong, but it's my understanding that 60FPS means LOCKED at 60fps (between 59 and 61 maybe). And 30fps means LOCKED at 30.
No dynamic FPS.
That's what I thought too, but Steam tells me it's running between 130-144, and it definitely feels like it too. I'll put up a screenshot when I'm back on my PC.
I think pacpes is right, the 60FPS option just means it'll let the frame rate go as high as your refresh rate