Do you mean duration and not speed?

Sure the readout gives a max speed reached but the numbers they compete over, and the numbers which establish car classes, are the time duration for the 1/4mi run.

Dragsters definitely measure their acceleration for bragging rights, it's usually a 0-100mph metric though. And of course bragging rights mean nothing if your car doesn't win the actual race. Top-Fuel dragsters race only 1000ft because they're so insanely fast it's dangerous to let them go farther and build up even more speed.