Full disclosure: I work as a Software Engineer for Ghost Games and was involved in the development of Need For Speed (2015). I am not an official spokesperson for Ghost or EA and I am not authorized to speak on their behalf.
In Need For Speed, AI racers will slow down when you're behind and speed up when you're ahead. The idea was to always make the player feel like they were having a fun challenge, regardless of skill level.
In the end, the AI rubber banding was such a strong effect that, when the game first came out, it was one of the main complaints. We ended up fixing it in the very first patch.
IGN reporting on it: http://www.ign.com/articles/2015/11/23/need-for-speeds-most-... Our announcement which first mentioned it: http://www.needforspeed.com/en_AU/news/future-plans