So before Cortana started showing me my commute times, I was using the commute feature on HERE Drive+ in order to display commute times on the live tile (which Cortana does now too). Just for kicks I started comparing both their recommendations on my commute home and I've noticed that Cortana seems to be a bit more accurate in her predictions. For example yesterday's commute on the I-5, Cortana told me it would take 31 minutes with 12 minutes traffic whereas HERE Drive+ told me it would take 30 minutes with no traffic. I'm guessing that they both get their info from different sources?