it. Some highways may be partly decommissioned, such as two segments of M-21 in Michigan from Holland to Grand Rapids as Interstate 196 and between Flint and the Canadian border at the Blue Water Bridge as Interstate 69 (I-69) supplanted much of it and M-21 remained in existence between Grand Rapids and Flint. US 33 in Lancaster, Ohio, was signed as US 33 Business following relocation of US 33 and construction to Interstate Highway standards. Other highways have been wholly decommissioned in favor of newer Interstates, as was the case with Texas State Highway 9. However, the reverse can also be done, such as I-170 in Baltimore being removed in favor of US 40 (which was previously routed on parallel-running one-way streets) because its parent route (I-70) had been cancelled due to longstanding opposition. Some state routes built on freeway alignments may be upgraded to Interstate Highway standards (or already built to Interstate standards) and receive Interstate designation, such as the case with Pennsylvania Route 60 being largely replaced by I-376. On the other hand, some routes are downgraded, as with US 61 in Minnesota, which became Minnesota State Highway 61 from Duluth to the Canadian border. At times, a state can abandon a number as the reason for state maintenance of the entire route no longer exists; Arizona transferred the short Arizona State Route 62 to the Mohave County government after a mine in Chloride closed and so did the economic purpose of the town. At the extreme a decommissioned route may be demolished, as was done with California State Route 480. Once part of the Interstate Highway System, it required retrofitting to remain in service after the 1989 Loma Prieta earthquake to remain in use; instead the highway was demolished. "Alternate", "Bypass" and suffixed routes (such as US 6A in Connecticut, the old US 71 bypass around Kansas City that disappeared in favor of Interstate 435 and Missouri Route 291, and the former US 30S in Ohio) have often been redesignated as lesser routes, in accordance with a policy of the AASHTO that now deprecates such highways, especially if short and confined to one state. Some states have decommissioned state highways which were within a state-numbered system because significant parts of those highways were not up to state standards, such as being unpaved and unlikely to ever be paved, as with Nevada State Route 49. Indiana removed all