They've had "expect heavy traffic" signs up as far away as the 11-28 rotary. I've got a Monadnock trip scheduled for Saturday; ugh, I'm going to be going right through it. EDIT: oh, good, race proper's Sunday. Equivalent of JoshandBaron's link: https://www.nh.gov/dot/media/nr2017/2017-09-18-nascar-traffic-plan.htm