Billboards Are Outdoor Advertising Displays Regulated Under California Law

A billboard is one type of outdoor advertising display. Signs commonly called “billboards” are more formally referred to in state and federal statutes as outdoor advertising signs or displays. Outdoor advertising signs are described, classified, and designated in different ways under state and local laws in California and nationwide. How they are characterized influences how they may be permitted, regulated, located, relocated, and maintained. In California, the legal framework governing outdoor advertising includes California’s Outdoor Advertising Act and Code of Regulations and the local zoning and municipal ordinances that regulate the city or county where the sign is built. Most states in the nation have their own outdoor advertising act designed to implement federal standards through state regulations. Understanding how different types of advertising signs are characterized and defined gives context to how regulatory requirements apply to them.

On-Premise and Off-Premises Advertising Signs

One primary legal distinction between outdoor advertising signs is their use as either an on-premise and off-premises sign. Generally speaking, an on-premises sign (aka an on-site sign) is the kind that advertises only the goods, services, or activities conducted on the property where that sign is located. The sign and what it advertised are located on the same property. Off-premises signs (aka off-site signs) advertise all those goods, services, activities and businesses available elsewhere than at the premises where the sign is located.

California’s Outdoor Advertising Act, administered by the California Department of Transportation (Caltrans), primarily regulates off-premises advertising displays located along and visible from state highways. These displays are subject to specific state permitting, spacing, zoning, and location parameters. On-premises signs are primarily regulated at the local level through zoning ordinances and municipal sign codes, which address size, height, placement, lighting, and use. State or federal considerations may also apply if the sign is visible from certain highway systems, in which case additional standards or restrictions may also be imposed.

Static and Digital Displays

Advertising displays are also commonly referred to as static or digital. Static signs display fixed advertising copy that does not change images or messages and is typically manually replaced after weeks or months. Digital signs, frequently identified in statute and regulation as electronic billboards or changeable message signs, display content using digital message technology that may change the message several times in one minute.

Digital displays are frequently subject to additional regulatory requirements concerning illumination levels, message duration, transition timing, and spacing from other advertising displays. In many jurisdictions, conversion from a traditional static display to a digital display requires new government approvals, and in some circumstances may only be legally permitted through conditional use permits, relocation agreements, development agreements, operating agreements, and other entitlements, all strictly regulated by state statutes and local ordinances. How static and digital displays are treated can vary greatly from one jurisdiction to another, depending on a variety of factors, including, but certainly not limited to, location, highway visibility, and the goals, purposes, intent, and limitations of the applicable sign regulations.

Conforming and Nonconforming Billboards

Another important legal distinction is whether a billboard is conforming or nonconforming. A conforming billboard complies with current state and local regulations governing its location, spacing, permitting, and operational requirements. A nonconforming billboard is a sign that was lawfully erected under the regulations in effect at the time of construction, but no longer complies with current standards due to subsequent changes in the law.

Under California law, lawfully erected nonconforming billboards are generally protected and allowed to remain despite changes in the regulations that permitted them. However, nonconforming status often restricts relocation, substantial reconstruction, expansion or modernization and even replacement after destruction. Whether a structure retains lawful nonconforming status depends on statutory definitions, permitting history, and regulatory interpretation.

Temporary, Relocation, and Replacement Structures

California law also addresses temporary displays, relocation units, and replacement structures. In certain circumstances, state statutes authorize relocation of a lawfully erected billboard when removal is required for public projects, including highway improvements. Relocation is subject to specific statutory requirements, including compliance with spacing rules, visibility standards, and permitting procedures administered by Caltrans and the local sign codes as well.

Replacement and modernization of existing signs is also governed by statutory and regulatory criteria. Whether a proposed change is characterized as repair, reconstruction, replacement, or new construction can affect how it is evaluated under applicable law. For example, if a display is destroyed beyond a statutory threshold (often expressed as a percentage of value or structural components), the right to rebuild may be lost. While routine maintenance is permitted, new placements and enlargements might not be.

Federal and State Regulatory Interplay

The Federal Highway Beautification Act establishes standards for outdoor advertising along interstate and primary highway systems. California implements these federal requirements through its Outdoor Advertising Act and related regulations. Federal law required each state to exercise “effective control” over outdoor advertising along the Interstate and Federal-Aid Primary System. States that fail to do that risk losing 10% of their federal highway funding. In 2022, California’s Governor reported that could be a reduction of over $400MM annual federal transportation funding. Some California statutes address this risk with express language incorporating federal oversight or approval.

Local sign ordinances are often stricter than state law. In California, the Outdoor Advertising Act permits this. Always review local rules because they may further restrict location, zoning, size, height, spacing, lighting (static or digital), design, permits, and other required approvals for advertising signs and billboards.

Why Classification Matters

How a billboard is classified determines how it is regulated. Permit eligibility, spacing, lighting standards, relocation rights, and enforcement procedures often turn on whether a display is on-premise or off-premise, static or digital, conforming or nonconforming, or subject to relocation rules.

Regulators rely on these classifications when reviewing applications and assessing compliance. Because the categories are defined by statute and regulation, accurate classification establishes the legal framework that will govern the advertising structure.

Legal Context for Billboard Classifications

Hamlin | Cody advises clients on all aspects of outdoor advertising displays. We interpret and apply the laws that regulate billboards and other outdoor signage.

If your project involves a billboard or any form of outdoor advertising, we provide clear, practical guidance on permitting, regulatory compliance, and proper classification under the Outdoor Advertising Act and related laws.