Section 21 of the Principal Act is amended as follows:

(a) by omitting "an accident" , twice occurring, from subsection (1) and substituting "a motor accident" ;

(b) by inserting "motor" in subsection (1) before "accident" , third, fourth and fifth occurring;

(c) by inserting "motor" in subsection (2) before "accident" ;

(d) by omitting "an accident" from subsection (3) and substituting "a motor accident" ;

(e) by inserting "motor" in subsection (3) before "accident" , second occurring.