I-94: 8 (really needs an extra Montana location) 7 are under construction
I-40: 3, although I believe will need 4 with the actual locations chosen.
I-15: 2 Helena, MT and Great Falls, MT are under construction. The 3rd, Shelby, MT makes the Canadian connection.
I-25: 1. Casper, WY has been a long time coming.
I-29 (not I-35): 4 (5 to Winnipeg). Fargo is under construction and also needed for I-94.
I-35: 1 Emporia, KS is under construction
To be honest, I think that serious questions need to be asked why Arkansas isn't done already. Some of the others are obviously less-traveled routes, but I can't believe I-40 isn't done yet, without there being a legal issue in Arkansas.