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