Interstate 175 Florida
Interstate 175 (South Bay Drive) constitutes an urban freeway connecting I-275 with Tropicana Field and Downtown St. Petersburg. I-175 is one-tenth of a mile longer than nearby Interstate 375 (North Bay Drive). The spur doubles as Florida State Road 594, which extends one block east of the freeway end to SR 687 (3rd Street S) north.
Serving the St. Petersburg Innovation District, a new ramp opened from 4th Street S northbound to I-175 west by Summer 2017. Planned since 2005, the $600,000 project was funded by the Florida Department of Transportation (FDOT). The connection improved access to the Interstate system from Johns Hopkins All Children’s Hospital, the University of South Florida St. Petersburg and the Dali Museum.1
When Interstate 75 was relocated to the east Tampa bypass in Hillsborough County in the late 1970s, five miles of eligible Interstate mileage became available for use elsewhere in Florida. Some of this unused mileage was allocated for the South Bay Drive spur to Downtown St. Petersburg (Interstate 175).
South Bay Drive was constructed in tandem with North Bay Drive (I-375) in two phases between 1977 and 1980. Work on the final link for the freeway, between 9th Street S (Martin Luther King, Jr. Street) and 4th Street S, commenced in 1977. Interstate 175 opened to traffic without fanfare on July 23, 1980 at total cost of $8.5 million.2
Source: December 31, 2021 Interstate Route Log and Finders List
I-175 Annual Average Daily Traffic (AADT)
|Vehicles per day||Location|
|46,000||I-275 to MLK St S|
|28,500||MLK St S to 6th St S|
|22,500||6th St s to 4th St S|
Source: 2019 AADT – Florida Traffic Online
FDOT submitted to applications to the American Association of State Highway and Transportation Officials (AASHTO) for the formal establishment of both I-175 and I-375 on April 21, 1981.
This spur route, to be designated Interstate 175, functions as a connector route that provides access between Interstate 275, the St. Petersburg Central Business District and the Urban Highway network.
Specifically, this route is 1.439 miles in length and is a limited access four-lane facility built to Interstate standards. The west end of this route connects to Interstate 275 and continues to provide direct access to a principal arterial (SR 687/U.S. 92).
AASHTO rejected both routes, citing a lack of approval by the Federal Highway Administration (FHWA) in a letter dated July 1, 1981. Designating I-175 and I-375 as logical additions to the Interstate System, FDOT received concurrence from the FHWA following a formal request on September 3, 1981. A succeeding application for I-175 and I-375 to AASHTO was approved on November 20, 1982.3
East End – St. Petersburg, Florida
Succeeding half diamond interchanges with MLK, Jr. Street S/8th Street S and 6th Street S precede the freeway end where I-175 shifts onto 5th Avenue S at SR 687 (4th St S). 04/03/20
4th Street S north at
4th St S north at the east end of I-175 and SR 594 (5th Avenue S). 10/08/17
East End Throwback
West End – St. Petersburg, Florida
- “New downtown St. Pete on-ramp expected to be a boon for Innovation District.” Tampa Bay Business Journal (FL). March 15, 2017.
- “I-275 south feeder is open downtown.” St. Petersburg Times (FL), July 24, 1980.
- American Association of State Highway and Transportation Officials (AASHTO) Route Numbering Committee Meeting, November 20, 1982 (document).
Page updated October 22, 2020.