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.