Running the business · October 10, 2026 · 6 min read
NAICS Codes and Size Standards for Traffic Control Companies
Flagging, barricade rental and sign installation each sit under a different NAICS code, and each code carries a different SBA small business size standard. Here is where the Census Bureau's index places traffic control work, what the size standards are, and where the choice of code shows up in registrations and bids.
By The Key Bot
In this article+
A traffic control company usually does three or four different kinds of work under one roof. It supplies flaggers. It rents barricades, drums and message signs. It may install permanent signs or guardrail. It may run pilot cars or attenuator trucks.
The federal classification system treats those as different industries. Each has its own six-digit NAICS code, and each code has its own small business size standard. Which code you use affects registrations, set-aside eligibility, some certification applications, and how lenders and insurers describe you.
This post explains where the official index places traffic control work and what the size standards are. It is general information. It does not tell you which code your company should use or whether you qualify as small for any program. Requirements vary by program and agency, so verify them with SBA, the certifying agency or the contracting officer.
What a NAICS code is
NAICS is the North American Industry Classification System. Federal statistical agencies use it to classify business establishments by their primary activity. The Census Bureau maintains it and publishes an alphabetical index that maps specific activities to codes.
Nobody issues you a NAICS code. You select it when you fill in a tax return, a state registration, a SAM.gov profile or a certification application. That is why companies in the same trade end up with different codes, and why the choice deserves ten minutes of thought.
Where the index puts traffic control work
The Census Bureau's 2022 NAICS index file lists activities by name. Four entries matter to this trade.
| Activity as indexed | NAICS code | Industry title |
|---|---|---|
| Flagging (i.e., traffic control) services | 561990 | All Other Support Services |
| Traffic control equipment (e.g., barricades, cones, traffic signs) rental or leasing | 532490 | Other Commercial and Industrial Machinery and Equipment Rental and Leasing |
| Sign erection, highway, road, street, or bridge; guardrail construction; traffic lane painting | 237310 | Highway, Street, and Bridge Construction |
| Sign erection other than on highways | 238990 | All Other Specialty Trade Contractors |
Two points stand out.
Flagging is classified as a support service, not as construction. A company that only supplies flaggers and sets temporary devices falls under 561990 in the index, even though all its work happens on construction sites.
Rental is its own industry. A company whose revenue is mainly device rental sits in the equipment rental and leasing sector.
Many traffic control companies do both, plus some permanent sign or striping work. That is where the idea of a primary code comes in.
Primary and secondary codes
Most registrations let you list several codes and ask you to name one as primary.
For SBA purposes, 13 CFR 121.107 describes how the agency determines a firm's primary industry. It considers the distribution of receipts, employees and costs of doing business among the different industries in which the firm operated in its most recently completed fiscal year, and it may consider other factors.
In practice, that points at where your revenue and your people actually are. If 70 percent of your receipts are flagging labor, a rental code as primary is hard to support. If your accounts cannot split revenue by line of work, you cannot answer the question with evidence. See job costing for traffic control companies and owner KPIs and reporting.
Listing secondary codes for the other work you perform is normal. It lets agencies and primes searching by code find you for each line of work.
The size standards
SBA sets a size standard for every NAICS code. For most service and construction industries it is a ceiling on average annual receipts. A firm at or below the ceiling is small for that code.
The table is at 13 CFR 121.201. For the four codes above:
| NAICS code | Industry title | Size standard |
|---|---|---|
| 561990 | All Other Support Services | $16.5 million |
| 238990 | All Other Specialty Trade Contractors | $19.0 million |
| 532490 | Other Commercial and Industrial Machinery and Equipment Rental and Leasing | $40.0 million |
| 237310 | Highway, Street, and Bridge Construction | $45.0 million |
SBA's table of size standards page notes that the current standards took effect on March 17, 2023. SBA revises them periodically, so check the table before relying on a figure.
The spread is wide. The flagging code's standard is $16.5 million and the highway construction code's is $45.0 million. A company with $20 million in receipts is small under one and not under the other. That is why the code matters.
How receipts are counted
"Annual receipts" has a defined meaning. Under 13 CFR 121.104, receipts means all revenue in whatever form received or accrued from whatever source, reduced by returns and allowances. The section explains that receipts are generally total income plus cost of goods sold as reported on IRS tax return forms.
It is also an average. For most programs, the annual receipts of a concern in business for five or more completed fiscal years means total receipts over its most recently completed 5 fiscal years divided by 5. Newer firms use a calculation based on the time they have been in business.
Two consequences for a growing company:
- One big year does not immediately push you over a standard, because the figure is averaged.
- Affiliates can count. SBA's rules combine a firm's receipts with those of its affiliates in many situations. If you own or are owned by another company, get advice before certifying your size.
Where the code shows up
SAM.gov registration. Federal contractors list their codes in the System for Award Management. SBA's size standards page notes that registered businesses must update their SAM registration to have their small business status updated under new size standards.
Solicitations. On a government contract, the agency assigns a NAICS code to the solicitation. That code's size standard governs who is small for that procurement. Your own primary code does not change it. A traffic control package might be solicited under a construction code, a support services code or a rental code depending on how the agency sees the work. Read the solicitation and ask the contracting officer if the code looks wrong.
Small business and DBE programs. State DOT certification applications ask for NAICS codes and certify you for specific types of work. The Disadvantaged Business Enterprise program has its own size rules as well. See DBE certification for traffic control companies.
Prequalification. Some DOTs classify contractors by work type using their own categories, which map loosely to NAICS. See DOT prequalification for traffic control contractors.
Insurance and workers' compensation. Insurers use their own classification systems, not NAICS, but the description of operations on your application should agree with how you describe yourself elsewhere. See workers' compensation classification for traffic control companies and insurance and bonding for traffic control contractors.
Lenders and benchmarking. Banks and industry reports group companies by code. A flagging company filed under highway construction gets compared with paving contractors, whose margins and asset bases look nothing like its own.
Questions to work through
- What share of last year's receipts came from labor, from rental, and from installed work?
- Does the primary code on your tax return, your state registration and your SAM.gov profile agree?
- Are all the lines of work you actually perform listed as secondary codes?
- What are your average annual receipts over the last five completed fiscal years?
- Do you have affiliates whose receipts might be combined with yours?
- For the agencies you bid to, which codes do they use for traffic control packages?
Take the answers to your accountant. A wrong size certification on a government contract is a serious matter, and the rules around affiliation and averaging are detailed. This post is an orientation, not a determination.
Keeping revenue split by line of work
The practical requirement behind all of this is knowing your revenue by activity. If every invoice is a single lump, you cannot show where your receipts come from.
Traffic OS quotes and invoices by line item, so flagging labor, device rental and other work are separated on the invoice and can be reported separately. It syncs invoices to QuickBooks Online, where your accountant can map them to income accounts. Pricing is flat by tier at $499, $949 or $1,499 per month as of October 2026, with no per-user charge. See pricing and features, or read traffic control software QuickBooks integration.
If you are just setting up, see how to start a traffic control company.
Frequently asked questions
What is the NAICS code for flagging services?+
The Census Bureau's 2022 NAICS index lists flagging (i.e., traffic control) services under 561990, All Other Support Services.
What is the NAICS code for barricade and traffic control equipment rental?+
The 2022 NAICS index lists traffic control equipment rental or leasing, with barricades, cones and traffic signs given as examples, under 532490, Other Commercial and Industrial Machinery and Equipment Rental and Leasing.
What is the SBA size standard for a traffic control company?+
It depends on the code. In the table at 13 CFR 121.201, the size standard is $16.5 million in average annual receipts for 561990, $40.0 million for 532490, $45.0 million for 237310 and $19.0 million for 238990. A solicitation names the code and standard that apply to that contract.
Can a company have more than one NAICS code?+
Yes. A company with several lines of work can list several codes in registrations such as SAM.gov. One is treated as primary. SBA's regulation at 13 CFR 121.107 describes how it determines a firm's primary industry.
Who picks the NAICS code on a government contract?+
The contracting agency assigns a code to the solicitation, and that code's size standard applies to the procurement. Your own primary code does not override it. Ask the contracting officer if the assigned code looks wrong for the work.