What was the problem with the Jefferson Davis school bus in Roll of Thunder, Hear My Cry?

The Jefferson Davis school bus didn't have a "problem,"
per se. The Logan family (and other African-American families in the area), had an
"issue," with the bus, namely that as it carried its white students to the school, the
bus driver intentionally tried to veer the vehicle toward the African-American school
children who were walking to their school.

Eventually, the
Logans would devise a plan to get revenge on the bus and its
occupants.