We're in Plainfield. We would normally go down 67 to Martinsville, then over to 37. Should we stay on 67 to 46 to 37? Is it better to go through center of Bloomington? Or should we just leave an hour earlier?

I'd go into bloomington ... via 10th and the bypass and swing around the backside of town. Hwy 37 is terrible after 4 especially on a Friday due to single lane heading north and south starting at tapp road .

I'd most certainly take 67 and jump over onto 37 in Martinsville. 67 goes way off course and you'll easily be adding 20-40 miles to your trip if you stay on 67 and then go down to Spencer then back across. Construction isn't really bad until you get to West-Central Bloomington on 37 at around Tapp Road where the construction traffic backs up to as it files down to one lane by the next red light. Which is a good 2 miles past where 46 meets 37 anyways. So no real gain going way over there. Stay on 37 and you can either get off at the Walnut street exit and follow that all the way down to Fairfax Rd and turn Left, or get off at the 45/46 Junction towards Bloomington (One exit is for Bloomington, the other Ellitsville) Then turn right onto N College Rd (which will eventually merge and become S.Walnut). The N College Rd. Redlight is the massive intersection after the N Kinser Pike light. After you turn Right onto N College, you can follow that to Fairfax.

Traffic does tend to be crap in the construction zone from 5-6pm especially. So if you want to risk it or are coming through a bit earlier than that, give yourself an extra 30 minutes or so, just in case, and you can go through the construction zone and turn Left on Dillman road just as the construction zone ends. Then Turn Left onto S. Walnut and head up to Fairfax and turn Right. (Both lefts will be Flashing lights, the First Yellow, the 2nd Red)

Either way you come, safe travels