California C-31 Construction Zone Traffic Control Exam
Free study guide and practice questions for the California CSLB C-31 Construction Zone Traffic Control exam — work-zone signs and devices, tapers and TTC zones, flagging, changeable message signs, and OSHA worker safety, built from the public 2026 California MUTCD, Caltrans sign charts, and OSHA standards.
Your progress
The C-31 Construction Zone Traffic Control license covers preparing and removing lane closures, flagging, and traffic diversions using portable devices — cones, delineators, barricades, sign stands, flashing beacons, arrow boards, and changeable message signs — on roadways. To get the license you pass a trade exam in addition to the Law & Business exam.
The CSLB exam outline weights the trade exam roughly like this: Planning & Estimating (~18%), Notifications & Coordination (~11%), Traffic Control Installation (~51%), Transportation & Training (~8%), and Safety (~12%). Installation is more than half the exam, so the topics below put the most practice there — signs and devices, tapers and zones, and flagging.
Everything here is built from public, freely reusable sources: the 2026 California MUTCD (Part 6, Temporary Traffic Control), the Caltrans Sign Charts, the Caltrans Changeable Message Sign Guidelines, and OSHA’s construction standards (29 CFR 1926). Work through the topics, then take a full timed practice exam to see where you stand.
Study by topic
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 →02Notifications, 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 →03Work-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 →04Channelizing 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 →05Flagging 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 →06Transportation & 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 →07Worker Safety & PPE
C-31 study guide on work-zone worker safety: high-visibility apparel classes, OSHA accident-prevention sign colors, struck-by hazards and the Focus Four, and night-work lighting.
Read & practice →