Which States Require Ground Tire Rubber? | State Mandate Map

California is the clear state-level yes for highway asphalt; most other states allow, test, or specify ground tire rubber instead.

If you mean highway paving, the answer is tighter than many search results make it sound. California is the clearest state with a standing use requirement for crumb rubber in asphalt. Outside California, ground tire rubber usually appears in one of four forms: a material spec, a pilot job, a bid option, or a DOT paving choice.

That split matters. A state can lay plenty of rubberized asphalt and still stop short of requiring it by law. Take Arizona. The roads may use it often, yet that is not the same as a statewide command written into statute with annual usage levels.

So if your real question is, “Which states make agencies use ground tire rubber in road asphalt?” the working answer is California, while a wider group of states permit or publish specs for it. That is the distinction most readers need before they quote a rule, write a bid, or size up a policy claim.

Which States Require Ground Tire Rubber? In Highway Paving Rules

Right now, California is the standout. Its law directs Caltrans to use crumb rubber on an annual average basis across state highway asphalt work. The same law also says the target is met statewide, so every single project does not need crumb rubber.

Outside California, the wording usually gets softer. You will see states that:

• approve rubber-modified asphalt in their standard specs,
• run trial or demonstration jobs,
• use rubberized asphalt on selected highways, or
• leave the call to the transportation agency and project design.

That softer wording is why people end up mixing “used here” with “required here.” They are not the same thing. One points to practice. The other points to a standing rule.

Why This Question Gets Misread

Ground tire rubber sits at the crossroads of recycling policy and road-building specs. One page may talk about scrap-tire reuse. Another may talk about binder grades, mix design, or chip seals. A third may mention a pilot project from years ago. Put those together, and it can look like a mandate when it is only an allowed material.

There is also some old federal baggage in the mix. Back in the 1990s, the United States had a federal crumb-rubber push for asphalt, then that mandate was removed. Since then, states have moved at their own pace. Some kept building with rubberized asphalt. Some kept pilot work going. Some published specs but did not turn that into a blanket statewide rule.

That is why the clean way to answer this topic is by sorting states into buckets: required, allowed by spec, pilot or demo use, and regular agency use without a blanket requirement.

Current Rule Snapshot By State

Here is the plain-language map that helps most readers fastest.

State Or Level	Status	What That Means
Federal	No current requirement	The old federal mandate ended; states are free to decide whether to use crumb rubber in asphalt.
California	Yes	Caltrans must hit annual average crumb-rubber use levels across state highway asphalt work.
Arizona	No blanket statewide requirement found	Rubberized asphalt is widely used on many highway jobs, yet that is an agency paving choice rather than a standing statewide command.
Florida	No blanket statewide requirement found	State law allows demonstration work with ground rubber and pushes recycled-content review in DOT specs.
Texas	No blanket statewide requirement found	TxDOT keeps standard specifications for crumb-rubber paving applications, which is not the same as a use mandate.
Georgia	Published specs	Rubber-modified asphalt appears in published state specs, which means allowed use, not an across-the-board order.
Missouri	Published specs	State specs open the door to use, yet that still falls short of a blanket statewide requirement.
Virginia	Published specs	Rubber-modified asphalt is part of the specification set, not a state-law usage command.
Pennsylvania	Published specs	Published specs allow the material in practice, though that does not make it mandatory on all work.

A good way to read that table is this: only California lands in the firm “required” bucket for statewide highway asphalt use. The rest fall somewhere in the “allowed,” “specified,” or “used by agency choice” lane.

Two public sources make that split plain. California Public Resources Code Section 42703 sets annual average crumb-rubber use levels for Caltrans. The FHWA crumb rubber asphalt page says states are not required to use crumb rubber in asphalt paving.

Where Ground Tire Rubber Shows Up Without A Mandate

This is the part many articles blur. A state can be a heavy user of rubberized asphalt without making it mandatory. Arizona has been a strong real-world user on highways for years. Texas keeps formal paving specifications in place. Florida law leaves room for demonstration work and spec revisions tied to recycled materials. Those are real forms of adoption. They just are not the same legal answer as California’s statute.

That difference also changes how you should phrase the claim in a report, post, or bid memo. “Uses” is safe when the agency lays the material on projects. “Allows” fits when the specs permit it. “Requires” should be saved for a rule that actually tells the agency it must hit a usage target or must use the material under named conditions.

If you skip that wording check, you can make a state sound far more aggressive than it is. That is where bad summaries start.

What To Read Before You Call A State A Yes

When you are checking a state, read the rule in this order:

1. Look for a statute, not only a press release or recycled-material page.
2. Check whether the text says “shall” or “may.” That one word changes the whole answer.
3. See whether the rule applies statewide, on selected jobs, or only to pilot work.
4. Check whether the target is project by project or an annual average across the whole DOT program.
5. Read the material definition. Some rules cover crumb rubber in any qualifying asphalt product, while others point to a narrower mix type.

That five-step scan will keep you from turning a spec into a mandate, or a pilot into a statewide rule.

What The Labels Mean In Real Terms

The words used in state pages can look close on the screen. In practice, they mean different things.

Label	Plain Meaning	Reader Takeaway
Required	The agency must use it under a standing rule or target.	This is the strongest yes.
Allowed By Spec	The material is in the standard specifications.	It can be used, yet it is not mandatory.
Pilot Or Demo	The agency may run test or trial projects.	This shows interest, not a broad rule.
Agency Use	The DOT lays it on some roads by project choice.	Real use does not equal a legal command.
Statewide Average Target	The agency must meet a program-level usage mark over time.	This is how California’s rule works.

The Working Answer Most Readers Need

If your topic is state highway asphalt, California is the state you can point to with confidence as a true requirement state. Other states may have strong rubberized-asphalt programs, active specs, or long-running use on highways. That still falls short of the same legal posture.

So the safe, accurate wording is this: California requires crumb rubber use in Caltrans asphalt work on an annual statewide basis. Arizona, Florida, Texas, and several other states use or specify ground tire rubber, yet public rule text points more to permission, specs, or agency choice than to a blanket statewide mandate.

That answer is tighter than the broad claims you see in recycled-tire marketing copy, and it is the version that holds up better when someone asks, “Show me the rule.”