This is my ideal. I know some will vehemently disagree, but in an arcade racer such as this, I'd have actually been disappointed if it was 60fps. Outdoor racing like this is all about the breathing vistas, visuals, lighting etc. Sacrificing a massive chunk of that extra layer of environmental scope and depth for some added smoothness imo is the wrong decision.
On a side note, if anyone lambasted DriveClub for going a locked 30fps, but is excusing Forza Horzon 2 on the basis of it being open world, I'm sorry, but what difference does being open world make to the actual gameplay smoothness when discussing the frame rate and response times? It doesn't. You're letting it off on some tertiary nonsensical semantics. Either a racing game is smooth and playable at 30fps or it isn't.
Fact of the matter is, Playground could have just reduced the graphical fidelity of the game to get it to run at 1080p/60fps, open world or not. Being open world, having dynamic global illumination, having more advanced lighting or thousands of geometric tree's, better textures, volumetric clouds etc etc, it's all just semantics when debating the merits of 30fps vs 60fps.