Historical clue formulations

• "Step on it!" — 2019-03-17
• When repeated, cry before "They're catching up!" — 2014-08-24
• Speed demon's cry — 1996-12-16
• Slave driver's exhortation — 1996-10-13
• "Step on it!" — 1995-09-10
• More expeditious — 1994-11-17