I know that the Acura Navs contiuously update the ETA based on the vehicle speed, but I think I noticed something else yesterday. I saw my travel times jump from an hour to an hour and a half withing 5 minutes. THis occurred as I was driving from the far northwest Chicago suburbs to downtown Chicago right as peak rush hour was beginning. I think it's because the express ways were updated on Nav traffic from green to red.

Anyone else notice this?

 

I notice it's based on average speed. Had you recently reset the average speed in your HID (say, tank up with gas or reset the button?) That will change ETA drastically.

 

Nope. It happened just as I was driving. Went from 53 minutes to 1 hour and 30 minutes and my speed didn't change that much when it changed. Sure enough about 15 minutes later the traffic reduced to a crawl, but the ETA changed well before that.