CDL Class A Study Guide

Inspect before every trip (pre-trip), during the trip (en route) and at the end (post-trip). Key standards from the CDL manual:

- Front tires need at least 4/32 inch of tread in every major groove; other tires 2/32 inch. - Steering play of more than 10 degrees (about 2 inches at the rim of a 20-inch wheel) is too much. - Check cargo and tie-downs within the first 50 miles, then every 3 hours or 150 miles and after every break. - Hydraulic brake check: pump the pedal three times, then hold it down for five seconds. It should not move.

Look 12 to 15 seconds ahead. Keep at least 1 second of following distance for every 10 feet of vehicle length below 40 mph, plus 1 more second above 40 mph — a 40-foot rig needs 4 seconds below 40 mph and 5 seconds above.

Total stopping distance = perception distance + reaction distance + braking distance (plus brake lag with air brakes). Slow down before curves, not in them. Empty vehicles can need longer to stop because they have less traction.

Hydroplaning can start at speeds as low as 30 mph. Bridges freeze before the road, and black ice makes the road look only wet. In fog, slow down and use low beams. At night, dim to low beams within 500 feet of an oncoming vehicle. Fatigue has only one cure: sleep.

When a stop is required, stop between 15 and 50 feet from the nearest rail and don't shift gears on the tracks. A typical tractor-trailer needs about 14 seconds to clear a single track.

Steering around a hazard is usually faster than stopping. If you must leave the road, avoid braking until you are down to about 20 mph. With a tire blowout, hold the wheel firmly and stay off the brake until the vehicle slows. Use escape ramps if your brakes fail on a grade. When stopped on the road, turn on the four-way flashers and set out warning triangles within 10 minutes: 10, 100 and 100 feet (ahead and behind) on a two-lane road; 10, 100 and 200 feet behind on a divided highway.

A BAC of 0.04% or more in a CMV disqualifies a CDL holder, and refusing an alcohol test counts as a positive. Texting and hand-held phone use are banned while driving a CMV. Placarded hazardous materials require the H endorsement. Carry a B:C fire extinguisher. Cargo needs at least one tie-down per 10 feet (never fewer than two).