Clive D. W. Feather wrote:
In article , Brimstone
writes
Units of frequency (Hz) are 1/seconds, so driver B, with
about (errm) 0.3e-7 ticket/s, as opposed to 0.1e-7 ticket/s
for driver A.
Except that in this instance "units of frequency" are miles per hour.

Nope: that's a unit of speed or velocity.

Quite, it represents the frequency with which a given unit passes over a
given distance.