What Is Considered a Highway?

A highway is commonly understood as a major road for fast, long-distance travel, but in many legal systems it actually means almost any publicly accessible roadway—including streets, roads, and bridges—open to general motor traffic. In everyday speech, people tend to reserve “highway” for higher-speed routes like freeways, expressways, and motorways, while the legal definition in many places is broader and includes ordinary city streets.

Core Definitions and How the Term Is Used

The legal sense

In transportation law, “highway” often refers to the full width of a public way maintained or open for vehicle travel, frequently including shoulders, verges, and structures like bridges. This definition matters for speed limits, enforcement, liability, and funding.

The everyday sense

In common usage, “highway” usually means a major intercity route built for higher speeds, with or without full access control—think U.S. freeways and expressways, or European motorways. This usage focuses on function and design rather than legal status.

How Different Jurisdictions Define “Highway”

United States

U.S. federal and state codes take a broad view of “highway,” while everyday language distinguishes freeways from ordinary roads. Key points vary by statute, but the themes below are consistent.

• Federal usage: Federal highway law treats a “highway” as a road, street, or parkway open to public travel, usually including associated structures and appurtenances.
• State vehicle codes: Many states define a “highway” as the entire width between boundary lines of any way publicly maintained and open to the public for vehicular travel (for example, California Vehicle Code §360).
• Common usage: “Freeway” or “interstate” denotes fully controlled-access highways with grade-separated interchanges and no at-grade crossings; “expressway” may have partial access control.

Taken together, U.S. law treats most public roads as highways, while drivers use “highway” to mean larger, faster routes—especially freeways and expressways.

United Kingdom

UK law uses a rights-based definition centered on public passage, which is broader than the lay understanding of a highway.

• Highways Act 1980: A “highway” is a way over which the public has a right to pass and repass, encompassing everything from country lanes to urban streets.
• Motorways: A specific, high-standard class of highway with controlled access and special rules (for example, cycling and certain slow-moving vehicles are prohibited).
• Trunk roads: Key national routes managed by central authorities; may be motorways or all-purpose roads.

In the UK, “highway” is a legal umbrella; “motorway” and “trunk road” signal higher strategic importance and stricter standards.

Canada

Canadian provinces define “highway” expansively, similar to many U.S. states.

• Provincial acts (e.g., Ontario’s Highway Traffic Act): “Highway” includes any common and public highway, street, road, bridge, or place intended for public vehicle passage, typically extending to the property lines.
• Colloquial usage: “Highway” often refers to numbered provincial or Trans-Canada routes; “freeway” denotes controlled-access segments.

Legally, most public roads are highways; colloquially, the word usually implies major intercity routes.

Australia and New Zealand

The statutory term frequently used is “road,” defined broadly, while “highway” is often a name or category in the network.

• Australia: State and territory road rules define “road” and “road-related areas” widely; major corridors may be called “highways” (e.g., Stuart Highway) but need not be controlled-access.
• New Zealand: The Land Transport Act defines “road” very broadly, covering areas open to public transport; “state highways” are nationally significant corridors under the NZ Transport Agency.

Functionally, a named “highway” is a principal route, but legal obligations often hinge on the broader “road” definition.

European Union and international conventions

The EU does not impose a single legal definition of “highway,” but standards and conventions shape usage.

• Motorways/Autobahnen/Autoroutes/Autostrade: High-standard, controlled-access roads with grade separation and restricted access.
• Express roads: High-capacity routes with some access control; standards vary by country.
• UNECE Vienna Conventions: Define “motorway” and “express road,” influencing sign systems and restrictions, though “highway” as a term is less formalized.

Across Europe, “motorway” is the consistent top-tier category; “highway” is more a generic English term than a legal label.

Types of Highways by Access and Function

Transportation planners classify highways by how traffic accesses them and how they connect places. This clarifies what drivers can expect in terms of speed, intersections, and safety features.

• Controlled-access highways (freeways/motorways): No at-grade intersections; entry and exit via ramps; medians or barriers; limited to motor vehicles; higher speed limits.
• Limited-access or expressways: Fewer driveways and intersections; some interchanges; may include occasional at-grade crossings.
• Arterials and trunk roads: Major surface streets connecting districts or towns; signalized intersections and at-grade crossings are common.
• Rural highways and national routes: Primary intercity links; may mix passing lanes, two-lane segments, and bypasses; access control varies.

These categories overlap in naming; a road signed as a “highway” might be a fully controlled freeway in one segment and a standard at-grade arterial in another.

Common Design Elements Associated with Highways

While not every highway has all of these, higher-class routes tend to incorporate more of the following design features to improve capacity and safety.

• Multiple lanes in each direction, with wider lanes and shoulders.
• Grade-separated interchanges (ramps, flyovers) instead of intersections.
• Medians or barriers to separate opposing traffic flows.
• Limited or no direct property access; fencing to prevent crossings.
• Restricted user classes (for example, no pedestrians, bicycles, or slow vehicles on motorways/freeways).
• Higher design speeds, gentler curves, and longer sight distances.

The more of these features present, the more likely the facility functions as a high-speed, long-distance highway rather than a local road.

What Typically Is Not Considered a Highway

Even under broad legal definitions, some ways fall outside the term or are treated differently for traffic law and liability purposes.

• Private roads not open to the public (gated industrial sites, farm tracks).
• Driveways and parking lots, unless a statute explicitly includes “road-related areas.”
• Trails and pathways reserved for non-motorized use.
• Temporary construction areas or closed roads not open to public travel.

Local law may still regulate behavior on these facilities, but they often sit outside the formal “highway” network used for public vehicular traffic.

Why the Distinction Matters

Whether a way is a “highway” affects rules, enforcement authority, and responsibilities for road users and owners.

• Traffic rules and restrictions: Some prohibitions (like on pedestrians or bicycles) apply only on motorways/freeways.
• Speed limits and signage: Set and enforced differently on highways than on local streets.
• Funding and jurisdiction: Eligibility for national/state funding and maintenance responsibilities often hinge on classification.
• Insurance and liability: Collisions and defects on a “highway” may trigger different legal standards than on private property.

Understanding the category helps drivers comply with the law and clarifies who is responsible for building and maintaining the road.

Quick Reference: Is This Road a Highway?

Use the questions below to quickly gauge whether a given road would be considered a highway in law or in common usage.

1. Is it publicly maintained and open to general vehicular traffic? If yes, it is likely a highway in the legal sense in many jurisdictions.
2. Does it have controlled access (ramps, no at-grade crossings, restricted users)? If yes, it functions as a freeway/motorway—definitely a highway in both senses.
3. Is it a numbered or signed intercity route with higher speeds and limited access points? If yes, most would consider it a highway in common usage.
4. Is it private, gated, or closed to the public? If yes, it generally is not a highway.

These checkpoints won’t replace a statute, but they mirror how engineers, police, and drivers differentiate highways from local roads.

Summary

Legally, many countries define “highway” broadly to include virtually any publicly accessible road, from small city streets to rural routes. In everyday language, however, “highway” usually refers to major, higher-speed corridors—especially controlled-access freeways or motorways. The exact definition varies by jurisdiction, but the practical distinction influences speed limits, access rules, funding, and liability. If a road is publicly open and maintained, it is often a highway in law; if it is high-speed with limited access, it is a highway in both law and common usage.

What’s the difference between a roadway and a highway?

In modern usage the term road describes a rural, lesser traveled way, while the word street denotes an urban roadway. Highway refers to a major rural traveled way; more recently it has been used for a road, in either a rural or urban area, where points of entrance and exit for traffic are limited and controlled.

What’s the difference between a highway and a route?

To sum up, routes are smaller, more localized roads, whereas highways are wider roads with a number designation.

What is the difference between a highway and a byway?

A highway is a (usually) a primary road. A byway is a secondary road. A freeway is a highway with controlled access (such as an interstate).

What is a highway vs freeway?

Freeway: In the U.S., this refers to a fully controlled-access, high-speed road with no intersections or stoplights. Highway: This is a broad term that includes all major types of roads, including freeways, expressways, and arterial roads.