According to a video posted by PixelEnemy; there's a simple fix for getting Need for Speed: Rivals to run at 60fps on PC.
Community members frustrated by the game running at 30fps have discovered the workaround which requires players to right click the shortcut for the Need for Speed: Rivals executable; select Properties, and then add the following line to the end of the Target entry:
-GameTime.MaxSimFps 60 -GameTime.ForceSimRate 60+
The process is said to work "almost flawlessly" though we haven't been able to test it. However, some users may need to lower their graphics settings to ensure a steady 60fps. Otherwise the framerate can drop to 50fps and is said to be "really sluggish".
Previous attempts to mod the game so that it runs at 60fps have led the cars moving at unplayable speeds. The PC version of Rivals has been criticised for its 30fps settings.