Worker Safety & PPE
Worker safety ties the whole C-31 zone together. The exam pulls from both the California MUTCD and OSHA’s construction standards.
High-visibility apparel
All workers in the TTC-zone right-of-way wear high-visibility apparel meeting ANSI/ISEA 107 Class 2 or 3; flaggers at night wear Class 3. Background color must be fluorescent orange-red, fluorescent yellow-green, or a combination.
OSHA signs and struck-by hazards
OSHA’s accident-prevention sign colors are worth memorizing: DANGER = red, CAUTION = yellow, safety instruction = green, exit = red on white. Under 29 CFR 1926, flagging, signals, and barricades for protecting employees must conform to the MUTCD — federal rules point straight back to the same Part 6 you study for the rest of this exam.
Work zones are a leading struck-by environment, one of OSHA’s Focus Four (Fatal Four) hazards along with falls, caught-in/between, and electrocution. Controls include trained workers, temporary barriers, speed management, and minimizing backing maneuvers.
Night work
When lighting is used for night operations, it must illuminate the work without creating glare that blinds approaching drivers.
Practice: Worker Safety & PPE
Frequently asked
What high-visibility apparel must work-zone workers wear?
What colors do OSHA DANGER and CAUTION signs use?
What are OSHA's construction Focus Four hazards?
More C-31 Traffic Control topics
Planning & Estimating Traffic Control
C-31 study guide on planning a traffic control zone: the four TTC areas, taper-length formulas, buffer space, advance warning sign spacing, and estimating devices.
Read & practice →Notifications, Permits & Coordination
C-31 study guide on permits and coordination for traffic control work: encroachment permits, 811/USA excavation notice, agency and public notification, and closure windows.
Read & practice →Work-Zone Signs & Markings
C-31 study guide on work-zone signs: orange sign color, sign shapes, common MUTCD codes (W20-1, W20-7, W3-4, G20-2), nighttime retroreflectivity, and changeable message signs.
Read & practice →Channelizing Devices & Arrow Boards
C-31 study guide on channelizing devices: cone and drum heights, barricade types, vertical panels, device spacing on tapers and tangents, and arrow board modes.
Read & practice →Flagging Operations
C-31 study guide on flagging: the STOP/SLOW paddle, paddle size, when a flag may be used, flagger signaling methods, and flagger station placement and night lighting.
Read & practice →Transportation & Training
C-31 study guide on transporting traffic control devices and training requirements: flagger training before assignment, what training covers, and where it is documented.
Read & practice →