> ## Documentation Index
> Fetch the complete documentation index at: https://docs.placematic.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How does HERE handle hazmat routing?

> Two separate parameters governing different things. Confusing them is the most common — and most consequential — hazmat integration error.

# How does HERE handle hazmat routing?

**Short answer:** Two parameters, and they are **not** the same thing.

* **`shippedHazardousGoods`** — an **array of cargo types**
* **`tunnelCategory`** — the **ADR tunnel restriction code** `B`, `C`, `D`, or `E`

<Warning>
  Supplying one does not imply the other. Confusing them is the most common hazmat integration error, and this is a domain where a software defect is a regulatory event.
</Warning>

## The values

**`shippedHazardousGoods`** accepts an array from:

`explosive`, `gas`, `flammable`, `combustible`, `organic`, `poison`, `radioactive`, `corrosive`, `poisonousInhalation`, `harmfulToWater`, `other`

**`tunnelCategory`** accepts a single value: `B`, `C`, `D`, or `E`. It governs which tunnels the vehicle may enter under ADR.

<Info>
  Verified against the [Matrix Routing v8 OpenAPI specification](https://matrix.router.hereapi.com/v8/openapi), v8.47.0, July 2026.
</Info>

**Physical constraints still apply.** A hazmat tanker is also a tall, heavy vehicle. Both constraint sets are required.

## Do not map a boolean

<Warning>
  `shippedHazardousGoods` is not `is_hazmat`. It's an array of eleven cargo types.

  Map your internal material classification against HERE's enum **deliberately**, with a documented mapping table, and **have it reviewed by someone qualified in the applicable regulation.**

  This is not a place to guess.
</Warning>

## Your system must be able to refuse

A routing request for a hazmat load without a class is not a request to route with defaults. **It is an invalid request.** Fail loudly.

<Warning>
  **An empty `routes` array on a hazmat request is not a bug.** It may be the correct answer: no permissible route exists between these points for this class.

  A system that retries with relaxed constraints, or falls back to car routing, has just produced an illegal route.
</Warning>

## Constraints belong to the load, not the carrier

The same tractor hauls dry van on Monday and hazmat class D on Tuesday.

`shippedHazardousGoods` is a property of **what is in the trailer**, and it changes per shipment. Vehicle dimensions belong to the vehicle record. Never hardcode either at a call site.

## Cache keys must include the constraint set

<Warning>
  An origin-destination cache key is a defect. Do not serve a route computed for one cargo class to a shipment carrying another.
</Warning>

## Record the map release

Restrictions change. A route computed in March against a March map may differ in September. If an incident occurs, you will be asked what the system knew and when.

## Common misconceptions

**"`B|C|D|E` are hazmat classes."**
They're tunnel categories. Different parameter, different meaning.

**"`category=lightTruck` exempts hazmat."**
It waives certain legal restrictions written for normal trucks. **It does not make a flammable liquid non-flammable.**

**"If no route is found, relax a constraint."**
That is how illegal routes reach drivers.

**"Google can do this."**
It offers no hazmat routing capability. Not a close comparison.

**"Regulatory data is uniform globally."**
Coverage and depth of hazmat restriction data vary by market.

## Test it

Ask your compliance officer for known-prohibited segments in your operating region. Assert that a routed hazmat vehicle avoids each. Put it in CI.

This is worth more than any amount of documentation review.

## Related

<CardGroup cols={2}>
  <Card title="Hazmat Routing" href="/use-cases/hazmat-routing">
    The full architecture, and refusing to route.
  </Card>

  <Card title="Truck Routing" href="/guides/truck-routing">
    Physical constraints, which also apply.
  </Card>

  <Card title="ELD Platform" href="/use-cases/eld-platform">
    Map release versioning as an audit artifact.
  </Card>

  <Card title="HERE vs TomTom" href="/comparisons/here-vs-tomtom">
    Both implement ADR tunnel codes. The taxonomies differ.
  </Card>
</CardGroup>

**HERE documentation:** [Routing API v8 reference](https://www.here.com/docs/bundle/routing-api-v8-api-reference/page/index.html)

***

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