SR 206 was legislated in 1931 to run from
pre-1945 SR 4 (US 1) in Cocoa east across the Indian River to Merritt Island. There it would split, with one leg running south to
Georgiana and the other north to
Courtenay. (In 1937, both of these branches from Merritt Island became part of
pre-1945 SR 219, later part of SR 3.) A 1935 law extended SR 206 west to Orlando along the planned
Cocoa–Orlando Highway, which used Lake Road in the Cocoa area. Plans made by the
State Road Department would have taken it into Orlando on Curry Ford Road (also defined as part of
pre-1945 SR 411 in 1939).
SR 70 was defined in 1933, running from SR 206 at Merritt Island east over the Banana River to
pre-1945 SR 140 at Cocoa Beach. A branch would run north along the west side of the Banana River to connect with
pre-1945 SR 219 at
Orsino. Finally,
SR 418 was defined along the existing Taylor Creek Road, running from
pre-1945 SR 22 at
Christmas south to the
Osceola County line, crossing the planned SR 206 about two-thirds of the way. By the
1945 renumbering, only the sections of SR 206 and SR 70 east of Cocoa were completed. SR 520 was defined to use sections of SR 418, SR 206 and SR 70. It would begin at SR 50 (former SR 22) near Christmas and run southeast along the general alignment of SR 418, switching to SR 206 where its planned alignment crossed. (SR 418 south of that crossing later became
SR 532.) From there it would take SR 206 to Merritt Island, and SR 70 the rest of the way to end at
SR 1 (former SR 140). The section west of Cocoa was built in the 1950s. It used very little of the existing Taylor Creek Road, instead being built further west, joining SR 50 much closer to Bithlo than Christmas. At some point,
Alafaya Trail was taken over from SR 50 north past the
University of Central Florida to downtown
Oviedo. SR 520 was extended west on SR 50 and then north on Alafaya Trail, ending at
SR 419 and
SR 426 in Oviedo. In the 1980s, SR 520 was truncated back to SR 50, and Alafaya became an extension of
SR 434. ==Major intersections==