Originally, there was no State Road connection between I-95 and Key Biscayne when the Interstate highway was opened in 1967. The southernmost exit of the expressway was a short "trunk ramp" forming the southwestern end of Southwest 23rd Road at Southwest First Avenue (with the ramps having an at-grade crossing with Florida East Coast Railroad tracks before reaching First Avenue). Southbound traffic for the Miami Seaquarium, beaches, and other tourist attractions along the Rickenbacker Causeway would exit at Southwest 23rd Road, then take Southwest First Avenue to Southwest 25th Road, which would lead (via Brickell Avenue) to the toll booths on the entrance of the Causeway.