Seeing and Communicating
What this domain tests
Seeing and Communicating tests your visual search pattern and your use of signals, mirrors, lights, and horn. A commercial driver must see hazards early and make intentions clear. The exam expects specific habits: scanning well ahead, checking mirrors on a cycle, checking blind spots before lane changes, and signaling early enough for other drivers to react.
Visual search
Look 12 to 15 seconds ahead in normal driving. In city traffic that is roughly one block; on the highway it is about a quarter mile. Scan the road surface, shoulders, signs, and intersections, not just the vehicle ahead. Look for brake lights several vehicles ahead, pedestrians near the curb, and vehicles entering from side streets. At night or in rain, reduce speed and increase your scanning distance because visibility and stopping distance both change.
Mirrors and blind spots
Check your mirrors every 5 to 8 seconds and before any lane change, turn, or backing maneuver. Mirrors do not show everything. Before changing lanes, signal, check the mirror, and turn your head to check the blind spot. On a large vehicle, the right side and the area directly behind the trailer are especially dangerous. If a vehicle disappears from your mirror, it may be in the blind spot, not gone.
Signals and warnings
Signal at least 100 feet before a turn in urban areas and earlier at highway speed. Cancel the signal after the turn. Use four-way flashers when you are stopped or moving slowly and are a hazard, but not as a substitute for turn signals. Tap the brakes to warn following drivers of a slowdown. Use the horn only to warn others, not to express frustration. At night, flash your headlights to signal presence, not to demand the right of way.
Worked example
You are driving a tractor-trailer on a multi-lane highway and want to move right. You check the mirror and see no vehicle, but the right mirror has a blind spot. The correct sequence is signal, check the mirror, turn your head to check the blind spot, and move only when the lane is clear. If a car is pacing in the blind spot, wait. The reasoning is that a mirror check alone is not a clearance check.
Traps that cost marks
Signaling after you start the maneuver gives others no time. Leaving a signal on confuses drivers and can cause them to pull out. Using the horn as a rebuke is not a warning. Do not assume a vehicle that is no longer in your mirror has passed you; it may be beside you.