Traction grades are an indication of a tire's ability to stop on wet pavement.
A higher graded tire should allow a car to stop on wet roads in a shorter distance than a tire with a lower grade. Traction is graded from highest to lowest as "AA", "A", "B", and "C".

Of current tires:

3% are rated “AA”

75% are rated “A”

22% are rated “B”

only 1 line of tires rated “C”