May 9th 1911
Thomas H. Flaherty, of Pittsburgh, PA, received a patent for a "Signal for Crossing", first U. S. patent application for a traffic signal design.
May 9th 1992
Roberto Guerrero, a Colombian race car driver set an Indianapolis 500 qualifying record, driving his Lola-Buick to an average speed of 232.483mph and setting the single lap record at 232.618mph.
Source:
The History Channel
Wikipedia