StacksVerified U.S. regulatory reference

49 CFR §234.253

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Each flashing light unit shall be inspected when installed and at least once every twelve months for proper alignment and frequency of flashes in accordance with installation specifications.
  2. (b)Lamp voltage shall be tested when installed and at least once every 12 months thereafter.
  3. (c)Each flashing light unit shall be inspected for proper visibility, dirt and damage to roundels and reflectors at least once each month.