Update: Wow, that was quick. We've just had feedback to this article from Ghost Games' Andreas Brinck, rendering lead on Need for Speed: Rivals - "I wanted to thank you for the excellent technical analysis of our game, but also ask for a small correction. The article states that the PS4 version of the game is missing ambient occlusion, but the fact is that the PS4 version actually is using it in the form of HBAO. Here are two screenshots from the PS4 demonstrating the difference between having it enabled (this is what's shipped and looking at the screenshots from the article it seems like this was in the build you played as well) and disabled. The effect is most visible on the exhaust pipes and the background, but can be seen on the armco as well."
Our mistake and we're happy to make the correction. Brinck has also clarified the Xbox One ambient occlusion and frame-pacing points. The latter issue in particular is our major concern with the game as it stands and we're happy that Ghost Games looks set to correct it in an upcoming update:
"The Xbox One version of is using the frostbite version of SSAO," he tells us. "The explanation for the frame-pacing is a bug in our settings, Even though the gameplay code is configured to run the game at 30Hz, the present interval of the renderer is incorrectly set to 1, which means that the renderer can present a frame at any multiple of 1/60 seconds. This will be fixed in an upcoming patch."