The long-awaited West Davis Highway opened today and I got a chance to drive it. Exit numbers on the new highway are:
1A - I-15 south
1B - SR 67/Legacy south
4 - 950 North, Farmington
7 - 200 North, Kaysville
9 - 2700 West, Layton
12 - 2000 West, Syracuse
13 - SR 127/Antelope Dr
15 - SR 193 (yes, there is no actual exit since the highway defaults into it, but it is fully signed as Exit 15. Similar to exit 24B northbound on Mountain View/SR 85 in Salt Lake City, which is a left turn across oncoming traffic.)
I-15: new exit 321.
SR 67: new exit 10.
SR 193 has also been extended west from its former endpoint at 3000 West, so that 193 and 177 currently end at the same place.
(EDIT: meant to post this in regular updates board. oh well)