In 1972 Florida asked AASHO* to assign a new US highway designation between US 1 at Titusville and US 19 at Weeki Wachee; following is the route description from the actual minutes of the meeting:
So why did Florida want to overlap a new US route designation on top of SR 50? Possibly it was because Florida wanted all of its most heavily-traveled routes to carry a US highway number. But for years AASHO* had been encouraging the states to eliminate all single-state US route designations (particularly those of less than 300 miles in length), so it seems likely that was the reason they denied this request. (Although one might well point out that just two years earlier they allowed US 57 to stand in Texas, a single-state route of only 98 miles.)
At any rate, if AASHO* had accepted the proposal, what would have been a good number to assign to this new US route? One possibility would be to recycle the US 94 designation. That route existed from 1926-1949, running across the peninsula between Miami and Naples, before it was redesignated as an extension of US 41.
However, some might argue that a two-digit US route number would not have been appropriate for a single-state highway of only 115 miles in length. So another idea would be to number the highway US 292, casting it as a "child" route of US 92 (which it would have intersected in Orlando), and a sibling to US 192.
What number would you have assigned? Leave your ideas in the comments below.
*AASHO became AASHTO in 1973.