| Before entering a curve | |
| Before starting up a grade | |
| Before starting down a grade | |
| Before exiting a curve |
| Brakes, air lines, brake lights | |
| Fuel tank, tire pressure, couplings | |
| Cab interior, tire tread, brake lights | |
| Headlights, signal lights, clearance lights |
| Brake drums that are cracked | |
| Damaged or heavily worn brake shoes | |
| All of these | |
| Oil, grease or fluid on the brake shoes |