(a) General rule.--Every citizen of this Commonwealth who is of the required minimum age for voting for State or local officials and who resides in the county shall be qualified to serve as a juror therein unless such citizen:
(1) is unable to read, write, speak and understand the English language;
(2) is incapable, by reason of mental or physical infirmity, to render efficient jury service; or
(3) has been convicted of a crime punishable by imprisonment for more than one year and has not been granted a pardon or amnesty therefor.
(b) Definition.--For purposes of this section, "convicted of a crime punishable by imprisonment for more than one year" does not include a conviction for any offense under or violation of the former act of May 1, 1929 (P.L.905, No.403), known as The Vehicle Code, or the former act of April 29, 1959 (P.L.58, No.32), known as The Vehicle Code, which offense or violation, if it had been committed after July 1, 1977:
(1) would have been substantially similar to an offense currently graded as a summary offense under 75 Pa.C.S. (relating to vehicles); or
(2) would not have been a violation of law.