CDL Combination Vehicles TestDriving Combination Vehicles SafelyMedium

You are driving a combination vehicle in heavy traffic and notice a car attempting to merge into your lane from an on-ramp, but you cannot see the driver in your mirrors. What is the most appropriate defensive driving action?

  1. AHonk your horn continuously until the car backs off.
  2. BMaintain your speed and assume the car will find another space.
  3. CSpeed up to close the gap and prevent the car from merging.
  4. DAdjust your speed or lane position to create a safe space for the merging vehicle.
Show answer & explanation

Correct answer: D. Adjust your speed or lane position to create a safe space for the merging vehicle.

Defensive driving requires anticipating potential hazards. If you cannot see a merging car's driver, they likely cannot see your truck. Creating space by adjusting speed or moving over (if safe) is the safest way to prevent a collision.

Why the other options are wrong

  • A. While a warning honk can be useful, continuous honking is aggressive and doesn't solve the problem of creating safe space; it can also startle the other driver.
  • B. Assuming another driver will find a space is negligent, especially when you know they are in a blind spot. This places the burden of safety entirely on the other driver.
  • C. Closing the gap is aggressive and significantly increases the risk of a collision, as the car may not have anywhere else to go.

Defensive Driving: Merging Traffic

Proactive actions to safely manage merging vehicles, especially when they are in blind spots.

  • Anticipate merges from on-ramps.
  • Assume other drivers cannot see your large vehicle.
  • Create space by adjusting speed or lane position.
  • Avoid aggressive maneuvers like speeding up or blocking.

Memory trick: Give a little space, save a life's grace.

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