Location: S Bismarck Expy and Main Ave, Mandan As the South Bismarck Expressway (unsigned I-194 and ND-810) begins, we’ll quickly approach I-94 Business. Location: S Bismarck Expy, Mandan Exit for I-94 Business.  E to I-194  E to ND-810  W to I-94, E to ND-1804  W to I-94 Bus, E to US-83/ND-1804  E to I-94 Bus