United States Permit Test Coach
Traffic signalsQuestion 115 of 223

A sign says WHEN FLASHING and has a flashing yellow beacon. When does the sign apply?

  1. At all times
  2. Only while the beacon is dark
  3. Only while the beacon is flashing
  4. Only at night
Show answer

Correct answer: Only while the beacon is flashing

A beacon with a WHEN FLASHING sign shows when the rule or condition is in effect. If the beacon is not flashing, the sign does not apply.

Source: Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD), 11th Edition with Revision 1 (FHWA, December 2025), Section 4S.03 Warning Beacon, page 793

Practice traffic signals

Questions last reviewed: 18 October 2026