The traffic on I-5 north of Sacto wasn't bad or even slow, just stupid. The air quality was horrid, though. Smog so thick you could cut it, and a strong ozone smell.

I-80 from Vacaville to Cordelia is pretty bad. There's almost as much smog and much more annoing traffic (mind you, it could be much worse). Serious patches of stop-and-go and probably 20 minutes lost.