I-94/194 in Bismarck-Mandan

[bugo]

Were I-194 and I-94 between BL 94 and the end of Main Street in Mandan built as a US 10 bypass? If so, why did they bypass this section in particular?

[Alps]

Though Historic Aerials has a gap from 1951-1964, it appears the whole area was built at once, meaning that it wasn't intended as a bypass so much as "US 10 traffic heading east" and "Bismarck traffic heading west" happening to be a mile apart.