Traffic-control contractor setting up a highway lane closure with cones and arrow board

Become a Licensed C-31 Construction Zone Traffic Control Contractor

The C-31 Construction Zone Traffic Control classification covers the temporary work that keeps roadway construction safe, lane closures, flagging, and the portable devices that route traffic around a job site.

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Requirements

Minimum age: 18+ is CSLB's normal applicant path. A minor may qualify only after a court appoints a guardian (BPC §7065.5)
Experience required: 4 full-time-equivalent years of journey-level experience within the past 10 years; CSLB prorates part-time work
Contractor bond: $25,000

About the Exam

Exam format: 2 parts (Law & Business + Trade)
Law & Business exam: 115 questions
School-observed scores: 65% Law / 71% Trade; not published as fixed by CSLB
Application fee: $450

License renews every 2 years. Governing code: CCR §832.31

About this classification

What does a C-31 Construction Zone Traffic Control contractor do?

A C-31 Construction Zone Traffic Control Contractor prepares or removes lane closures, flagging, and traffic diversions on roadways using portable devices, cones, delineators, barricades, sign stands, flashing beacons, arrow trailers, and changeable message signs. The C-31 manages the flow of traffic around a construction zone but performs no road construction itself.

Under the California Code of Regulations (Title 16, §832.31), a C-31 contractor "prepares or removes lane closures, flagging, or traffic diversions, utilizing portable devices…on roadways." This is the safety-and-control specialty that lets paving, utility, and engineering crews work next to live traffic.

Official source: CSLB C-31 classification · CSLB fee schedule Last reviewed: March 2026

Scope of work

Highway and street lane closures
Flagging operations and certified flaggers
Cones, delineators, and barricade placement
Sign stands and temporary construction signage
Flashing arrow boards and message-sign trailers
Flashing beacons and warning devices
Temporary traffic diversions and detours
Setup and teardown of traffic-control plans

Important notes

The C-31 uses portable devices to control traffic temporarily, it performs no road construction itself.
Permanent pavement markings, striping, raised markers, and guardrails are the C-32 (Parking and Highway Improvement) scope, not the C-31.
A C-31 commonly works as a subcontractor providing traffic control for C-12 (Earthwork and Paving) and A (General Engineering) prime contractors.
California requires a license for any traffic-control contract over $1,000 (labor and materials combined), and workers' compensation coverage is required once you have employees; sole owners with no employees may file an exemption (BPC §7125(b)).

The CSLB exam

What's on the C-31 Construction Zone Traffic Control exam?

California requires you to pass a two-part CSLB exam: the Law & Business exam (the same for every classification) and the C-31 Construction Zone Traffic Control trade exam. CSLS has observed scores of 65% for Law & Business and 71% for the C-31 trade exam. CSLB does not publish fixed passing scores and may vary them by exam version.

Law & Business

Same for all classifications

115 questions, multiple choice, computer-based
3.5 hours allotted
Topics: California contractor law, business management, safety, estimating, project management

C-31 Trade Exam

Construction Zone Traffic Control-specific

about 100 questions, multiple choice, computer-based
3.5 hours allotted
Topics: MUTCD and California traffic-control standards, lane-closure layout, flagging procedures, device placement, work-zone safety, plan reading

How to Get Your C-31 Construction Zone Traffic Control License

Step 1

Qualify

18+ is CSLB's normal applicant path. A minor may qualify only after a court appoints a guardian (BPC §7065.5). You also need a valid SSN/ITIN and 4 full-time-equivalent years of journey-level construction zone traffic control experience within the past 10 years; CSLB prorates part-time work. Up to 3 years may be substituted with approved education or apprenticeship.

Step 2

Apply to CSLB

Submit your application, get fingerprinted, and pay the $450 application fee. Processing times vary; check the CSLB's current processing times.

Step 3

Study & Prepare

Prepare for both exam parts, on your own or with a CSLS exam prep program. 99% of CSLS students pass on their first try, backed by our 100% Money-Back Guarantee.

Compare programs

Step 4

Pass the Exam

Two parts: Law & Business (115q, 3.5 hrs) + C-31 Trade. Multiple choice, computer-based. CSLS has observed scores of 65% Law & Business / 71% C-31 Trade; CSLB does not publish fixed passing scores and may vary them by exam version.

Step 5

Get Licensed

Post your $25,000 contractor bond, pay the $200 license fee, and receive your C-31 license. You're officially in business.

Step 1

Qualify

Step 2

Apply to CSLB

Submit your application, get fingerprinted, and pay the $450 application fee. Processing times vary; check the CSLB's current processing times.

Step 3

Study & Prepare

Prepare for both exam parts, on your own or with a CSLS exam prep program. 99% of CSLS students pass on their first try, backed by our 100% Money-Back Guarantee.

Compare programs

Step 4

Pass the Exam

Step 5

Get Licensed

Post your $25,000 contractor bond, pay the $200 license fee, and receive your C-31 license. You're officially in business.

Exam Prep Programs

Compare C-31 Construction Zone Traffic Control Exam Prep Programs

Every program prepares you for the required CSLB exam for C-31 Construction Zone Traffic Control. Our 99% first-time pass rate is backed by the 100% Money-Back Guarantee on eligible programs.

Feature-by-feature comparison of all four CSLS exam prep programs
Features	Most Popular All-Inclusive C-31 Construction Zone Traffic Control $1,195.00 Value: $2,500	Live Online C-31 Construction Zone Traffic Control $695.00 Value: $995	Crash Course C-31 Construction Zone Traffic Control $495.00 Value: $695	Home Study C-31 Construction Zone Traffic Control $295.00 Value: $395
Best For	Comprehensive prep with maximum support	Remote learners wanting live instruction	Experienced pros with an exam date soon	Self-directed independent learners
Law & Business Classes	4 Classes + Full-Day Review	4 Live Online + Review	Full-Day Review Only	Not included
Trade Math Training	30-Day Interactive + Review	Online Video Review	14-Day Crash Course	Not included
Test-Taking Skills Seminar	1-Day In-Person	1-Day Online	Not included	Not included
Law & Business Materials	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available
Trade-Specific Materials	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available
Study Materials	Full Online Suite	Online Materials + Audio/Video	Online + Audio/Video	Online + Audio
Online Videos	Full Suite: L&B, Trade, H&S, Math	Audio + H&S + Math Videos	Audio + H&S + Math Videos	L&B Audio + H&S Video
Law & Business Practice Exams	6 Months	2 Months	30 Days	30 Days
Trade Practice Exams	6 Months	2 Months	30 Days	30 Days
School Location Access	25+ Locations	25+ Locations	25+ Locations	Self-Study Only
Application Assistance	Preparation & Review	Review Only	Review Only	Not included
Money-Back Guarantee	Included	Included	Included	Not included
Bond Fee Discount	50% off first-year bond, up to $120	Not included	Not included	Not included
Retail Value	$2,500	$995	$695	$395
Choose a program	Get All-Inclusive	Get Live Online	Get Crash Course	Get Home Study

Not sure which fits? Call 800-809-6463. Prices and inclusions are subject to change.

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Common Questions

C-31 Construction Zone Traffic Control license FAQ

The C-31 (Construction Zone Traffic Control) handles temporary, portable traffic control, cones, flagging, and lane closures that protect a work zone and come down when the job is done. The C-32 (Parking and Highway Improvement) installs permanent markings, striping, raised markers, and guardrails. One is temporary control; the other is permanent installation.

No. The C-31 performs no road construction. Its entire scope is managing traffic around a construction zone using portable devices. The actual paving and grading is done by the C-12 or A prime contractor, and the C-31 typically works as their traffic-control subcontractor.

If you are contracting to set up flagging, lane closures, or traffic diversions on a roadway for more than $1,000, you need a C-31 license. The classification specifically covers preparing and removing these temporary controls using portable devices on roadways.

Most students are exam-ready in 4–6 weeks of CSLS prep. Adding CSLB application processing (typically 2–4 weeks), exam scheduling, and posting your $25,000 bond, the full path usually runs 2–4 months from start to license-in-hand.

4 full-time-equivalent years of journey-level construction zone traffic control experience within the past 10 years; CSLB prorates part-time work. Qualifying work may be as a journeyperson, foreperson, supervising employee, contractor, or owner-builder. This can include work as a journeyman, foreman, or supervising employee. Up to three years can be satisfied with approved technical training, apprenticeship, or education.

The C-31 trade exam covers traffic-control standards (MUTCD and California requirements), lane-closure layout, flagging procedures, and work-zone safety. You need the current version-specific CSLB passing score to pass. With CSLS exam prep, 99% of students pass on their first attempt, backed by our 100% Money-Back Guarantee.

Plan on roughly $885 in mandatory costs before exam prep: the $450 application fee, the $200 initial license issuance fee, about $150 for the first-year premium on your $25,000 bond, and around $85 for fingerprinting. Exam prep is separate.

Since 1985

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Students Licensed

99% Pass Rate

First-Time

100% Money-Back Guarantee

Tuition Refund

Become a Licensed C-31 Construction Zone Traffic Control Contractor

What does a C-31 Construction Zone Traffic Control contractor do?

Scope of work

Important notes

What's on the C-31 Construction Zone Traffic Control exam?

Law & Business

C-31 Trade Exam

How to Get Your C-31 Construction Zone Traffic Control License

Qualify

Apply to CSLB

Study & Prepare

Pass the Exam

Get Licensed

Qualify

Apply to CSLB

Study & Prepare

Pass the Exam

Get Licensed

Compare C-31 Construction Zone Traffic Control Exam Prep Programs

Labor Day Promo 2026

What our Construction Zone Traffic Control students say

Try a free C-31 Construction Zone Traffic Control practice exam

C-31 Construction Zone Traffic Control license FAQ

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