It is also designated as the unsigned highway State Road 594 (SR 594).

Westbound, the Interstate begins with a split from southbound 4th Street South just north of the 4th Street South/5th Avenue South intersection and has no exits until the interchange with I-275.

[1] The freeway was originally to have been a part of the former Pinellas Belt Expressway, which would have continued from its western terminus at I-275.

The Pinellas Belt Expressway was budgeted in 1974 but was canceled in the late 1970s due to local opposition.

[citation needed] The entire route is in St. Petersburg, Pinellas County.