Setup and Closure Flashcards

A flagger is setting up a work zone on a road with a 35 mph posted speed. Using the taper length formula for speeds under 45 mph (L = WS²/60), what is the minimum taper length if the lane width is 12 feet?

Answer: 245 feet

L = (12 × 35²) / 60 = (12 × 1225) / 60 = 14700 / 60 = 245 feet.

During a long-term lane closure lasting several days, what additional setup element is often required that is not needed for short-duration operations?

Answer: Positive protection barriers such as concrete or water-filled barriers

Long-term closures typically require positive protection such as concrete or water-filled barriers to provide physical separation between workers and traffic.

When closing a shoulder for work rather than a travel lane, which statement about advance warning requirements is correct?

Answer: Advance warning signs are still required, though spacing may be reduced

Shoulder closures still require advance warning signs, but the setup may be simplified compared to a full lane closure depending on site conditions.

At the end of the work day, the crew will resume work the next morning. Which devices may remain in place overnight according to California temporary traffic control standards?

Answer: Only devices that are weighted or anchored and equipped with retroreflective materials or lights

Devices left overnight must be properly anchored and have retroreflective materials or lighting so they are visible to nighttime drivers.

A supervisor asks a flagger to close a lane without the proper number of advance warning signs because they are unavailable. What should the flagger do?

Answer: Refuse and report the situation to the appropriate authority, as the setup does not meet safety requirements

Flaggers must not implement a setup that does not meet required safety standards; they should refuse and escalate to the appropriate authority.

What is the purpose of a shadow vehicle (truck) positioned with its arrow board during mobile or slow-moving work zone operations?

Answer: To act as a moving buffer that absorbs impact and directs traffic away from workers

The shadow vehicle with an arrow board serves as a moving buffer, absorbing potential impacts and providing directional guidance to protect workers ahead of it.

After a temporary lane closure is completely removed, what is the final responsibility of the flagger before leaving the site?

Answer: Verify the roadway is restored to its original condition with no devices or hazards remaining

The flagger's final duty is to confirm the roadway is fully restored — no cones, signs, or debris remain that could confuse or endanger drivers.