Green’s Dictionary of Slang

1. slow, clumsy.

1957

Life 9 Sept. 59: The bungling, lead-footed fellow who is so stupid that he cannot escape [HDAS].

2. speeding.

1982		J. Ellroy Clandestine 201: It took me a solid four hours of lead-footed driving to make it back.
1991		DayWatch 20 Dec. [CNN-TV] Efforts to crack down on lead-footed police [HDAS].