Interstate 375 (North Bay Drive) is a freeway spur connecting I-275 with U.S. 92/SR 687 (4th Street N) and U.S. 19 Alternate/SR 595 (5th Avenue N) on the north side of Downtown St. Petersburg. I-375 is one-tenth of a mile shorter than its southern counterpart, Interstate 175 (South Bay Drive). State Road 592 runs along the entire length of North Bay Drive, which extends east to U.S. 19 Alternate/SR 595 (4th Avenue N) southbound.
Interstate 375 was built between 1977 and 1979 in two phases. The first section opened to traffic on January 17, 1978.1 The remaining portion of the collector freeway was completed in September 1979.2 A ramp stub at the west end alludes to a previously proposed connection with 20th Street N.
North Bay Drive was prematurely signed as Interstate 375, based upon correspondence between the Florida Department of Transportation (FDOT) and the Federal Highway Administration (FHWA) on February 7, 1972:
The possibility of assigning special numbers should be considered; i.e., 182 and 184 or I-175 and I-375. This would simplify the signing and would be consistent with spurs of Interstate Highways which are identified with three digit numbers.
Based upon this, design and construction of North Bay Drive proceeded under the impression that FHWA had approved the route as Interstate 375. Additionally Federal approval and funds were authorized for I-175 and I-375 interchange guide signs along I-275.
A subsequent application from FDOT to the American Association of State Highway and Transportation Officials (AASHTO) on April 21, 1981 formally requested the additions of both I-175 and I-375 to the Interstate System. Both were rejected:
The proposed routings mainly serve traffic into the St. Petersburg central business district. Also, concurrent approval by the Federal Highway Administration would be required.
The FHWA eventually approved both I-175 and I-375, as they were constructed to Interstate standards and were part of the Federal-aid primary system. They were added as logical additions to the Interstate System under the provision of 23 U.S.C. 139(a). FDOT resubmitted I-175 and I-375 to AASHTO in an application on September 14, 1982. They were approved on November 20, 1982.3