What is “tar” on the road?

It’s the black, sticky binder you see on pavement and repairs—but in most modern roads it isn’t true coal tar; it’s usually petroleum-derived bitumen (often called asphalt) or crack-sealing material. Colloquially, people call any shiny, black road binder “tar,” whether it’s the bitumen holding asphalt together, the tack coat used before paving, or the rubbery sealant that snakes across repaired cracks.

What “tar” actually is

Historically, “tar” meant coal tar—a product distilled from coal. It was once used as a road binder but is now largely phased out in new road construction because of health and environmental concerns. Today, the black binder in most asphalt pavements is bitumen (also called asphalt binder), a petroleum product refined from crude oil. The everyday confusion arises because both materials look and behave similarly on the surface.

Common terms and how they differ

To understand what you’re seeing on a roadway, it helps to distinguish a few terms that are often mixed up in conversation and even in signage.

• Coal tar: A coal-derived product once used in road binders and some sealants; high in polycyclic aromatic hydrocarbons (PAHs) and now heavily restricted or phased out for roads in many regions.
• Bitumen (asphalt binder): A petroleum-derived binder that glues aggregates together to form asphalt concrete; this is what most modern roads use.
• Asphalt (asphalt concrete): The finished road material—bitumen plus stone and sand—that you drive on.
• Crack sealant (“tar snakes”): Flexible, rubberized sealant used to fill cracks and prevent water intrusion; often appears as shiny black lines on older pavements.
• Tack coat/bond coat: A thin layer of bituminous emulsion applied between layers of pavement to ensure they bond.
• Sealcoat/surface treatment: Protective coatings (often bitumen-based emulsions, sometimes chip seal with embedded stone) applied to extend pavement life; coal tar–based sealers are restricted or banned in many places.

In short, the black material most people call “tar” on active roadways is generally bitumen or a bituminous product; true coal tar shows up mainly in legacy pavements or older sealants and is increasingly regulated.

Where you encounter “tar” on roads

The black, sticky appearance can show up in several routine pavement applications and maintenance activities, each with a different purpose and performance profile.

• Base pavement: The binder in asphalt concrete is bitumen; you don’t usually see it separately unless the surface is new, hot, or raveling.
• Chip seal: A thin bituminous layer sprayed and immediately covered with small stone chips—common on rural roads for cost-effective preservation.
• Crack sealing: Soft, rubberized sealant poured into cracks to keep water out; often visible as dark serpentine lines (“tar snakes”).
• Pothole and utility patches: Fresh patches use hot mix or cold mix with visible binder at the edges, especially before stone dust wears in.
• Tack/bond coats: A thin, tacky bituminous emulsion applied before a new lift of asphalt; it can look like a uniform black sheen before paving.

If it’s shiny, raised, and in narrow lines, you’re likely seeing crack sealant; if it’s a uniform film or sticky layer before new asphalt is placed, that’s tack coat; if it’s embedded with stone, it’s usually chip seal or a fresh patch.

Safety, performance, and environmental notes

Bituminous binders and sealants are essential for durable pavements, but they come with practical considerations for drivers, cyclists, and road managers, as well as environmental health context.

• Traction: Crack sealant can become slick in heat or rain, posing a stability issue for motorcyclists and bicyclists; road agencies balance sealing benefits with surface texture treatments.
• Heat and stickiness: On very hot days, fresh or heavily sealed surfaces can soften and track; modern “trackless tack” products reduce pickup on tires and vehicles.
• Vehicle care: Fresh binder can splatter onto paint and wheels; prompt, gentle cleaning helps prevent staining or clearcoat damage.
• Health and environment: Coal tar contains high PAH levels and is restricted or banned in many jurisdictions (for example, statewide bans in Washington and Minnesota and a ban in the District of Columbia in the U.S.; coal tar–based road binders have been largely phased out in Europe and the U.K.). Bitumen is the standard binder today; while its fumes during hot application are managed with safety protocols, it does not carry the same PAH profile as coal tar.

These factors explain why you’ll see careful traffic control around paving work, specific product choices for maintenance, and regulations that limit the use of coal tar–based sealers and binders.

How to remove road “tar” from your vehicle

If black specks or smears end up on your car, timely and careful cleaning can prevent etching or long-term staining.

1. Let it cool: Park the car in shade so the residue hardens slightly and is easier to lift without smearing.
2. Use a dedicated remover: Apply an automotive bug-and-tar remover or a citrus-based cleaner to a microfiber towel; dab and gently wipe. Reapply as needed.
3. Avoid harsh solvents: Skip lacquer thinner or gasoline, which can damage clearcoat and plastics. If needed, mild mineral spirits can work, but test a hidden spot first.
4. Wash and protect: After removal, wash the area with car shampoo and water, then apply wax or sealant to restore protection.
5. Wheels and liners: For heavy deposits in wheel wells, use an all-purpose cleaner and soft brush, then rinse thoroughly.

If residue has cured for weeks or the surface is delicate (vinyl wrap, matte paint, or paint protection film), consider a professional detailer to avoid surface damage.

Bottom line

“Tar on the road” is a catch-all phrase for the black binders and sealants that make pavements stick together and last. In modern practice that’s typically petroleum bitumen, not coal tar, with crack sealants and surface treatments adding to the glossy black look you sometimes notice. These materials are essential for road durability, require sensible safety around heat and traction, and are subject to environmental rules—especially where coal tar products are concerned.