As you mentioned, the other data CE884 document was a remnant of the instantaneous speed change. Those top two entries were then changed from z161-z166 to z168-z171, right away an obvious frame change at the same distance, which adversely affects the speed. The speed for z168-z171 = 18.3/3 = 6.1 x .9ft = 5.49ft per sec = 3.74 mph = .3ft per frame The limo wasn't traveling at 3.74mph at this point either Removing alternating frames from a film where a vehicle is traveling at 3