It's been around for longer than decades and it wasn't originally developed by NASCAR.
NASCAR may have given it the SPEED TAPE name (when used for NASCAR vehicles), but the tape was around long before NASCAR existed.
I called it DUCT TAPE, but what I found interesting is that the original name of it was DUCK TAPE.
Some companies call it DUCK, some DUCT.
The tape was invented for use in sealing up ammo cases (for WWII).
It was called DUCK TAPE because water ran off it like water off the back of a DUCK.
During WWII, an adhesive canvas tape was also used to patch small holes about the size of those made by a German Mauser rifle or MG34/42 machinegun on the amphibious trucks used for ferrying troops to shore from larger craft, or for running the wounded back to hospital shop facilities.
The trucks were designated DUKWs, pronounced *Duck* by the GIs. Thus the repair tape was *Duck tape. The GIs found the tape handy for all sorts of other tasks, and a legend was born.