> ## 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.

# Does HERE support truck routing?

> Yes — and setting transportMode=truck is not how you use it. Omit the dimensions and HERE routes an unconstrained vehicle without warning.

# Does HERE support truck routing?

**Short answer:** Yes, and it's the strongest reason to choose HERE. But `transportMode=truck` selects the routing **engine**. It does not tell HERE how tall your vehicle is.

<Warning>
  Omit the dimensions and you get a route. It returns `200`. It contains a polyline. It may route a 4.1-metre trailer under a 3.4-metre bridge.

  **HERE will not warn you, because you did not tell it there was a trailer.**
</Warning>

## What HERE expresses

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

* **Dimensions** — `height`, `width`, `length`, `trailerLength` (centimetres)
* **Weight** — `grossWeight`, `currentWeight`, `emptyWeight`, `payloadCapacity` (kilograms)
* **Axles** — `axleCount`, `weightPerAxle`, and `weightPerAxleGroup` with `single`, `tandem`, `triple`, `quad`, `quint`
* **`tunnelCategory`** — ADR restriction code `B`, `C`, `D`, `E`
* **`shippedHazardousGoods`** — eleven cargo types
* **`kpraLength`** — kingpin-to-rear-axle, for California and Idaho
* **`category: lightTruck`** — a legal exemption that does **not** waive physical dimension limits
* `trailerCount`, `tiresCount`, `licensePlate` for environmental-zone evaluation

<Info>
  **Weight per axle *group* is the decisive parameter for US carriers.**

  Federal bridge formula and state limits are frequently expressed per axle group, not per axle. A five-axle tractor-trailer with a steer axle, a tandem drive, and a tandem trailer group cannot be described by a single per-axle scalar.

  Competitors that expose only a scalar `axleWeight` cannot determine route legality in those jurisdictions.
</Info>

## Units will catch you

| Parameter              | Unit            | A common wrong value            |
| ---------------------- | --------------- | ------------------------------- |
| `vehicle[height]`      | **centimetres** | `4.1` → a four-centimetre truck |
| `vehicle[grossWeight]` | **kilograms**   | `35` → a 35 kg truck            |
| `vehicle[axleCount]`   | count           | tractor only, omitting trailers |

**Units are not validated for plausibility.** Pass `4.1` and HERE routes a four-centimetre vehicle under every bridge in North America. `200`.

<Info>
  **`vehicle` supersedes `truck`.** The `truck` object is deprecated in the current v8 spec. `weightLimit` is deprecated in favour of `grossWeight`.

  If you're reading a 2021 tutorial, you're reading deprecated parameters.
</Info>

## Verify it actually applies

Route a 410 cm vehicle through the 11foot8 bridge (Durham NC), Storrow Drive (Boston), and the Southern State Parkway (Long Island).

**Any path returned is a failure.** Run the same three in `car` mode as a control.

**Put this in CI.** A refactor that drops `vehicle[height]` from a params dict is invisible in code review and obvious in a failing test.

## Common misconceptions

**"`transportMode=truck` is truck routing."**
It selects the engine. Both parts are required.

**"`category=lightTruck` waives dimension limits."**
It waives certain legal restrictions written for normal trucks. **Bridges do not care about your category.**

**"`axleCount` is the tractor's axles."**
It's the whole combination, including all trailers. Range 2–255.

**"200 means a valid route."**
`200` with an empty `routes` array means no path exists. For truck routing, "no legal route" is a **correct** answer. A system that retries with relaxed constraints has just produced an illegal route.

**"Google can do this if I add logic."**
It can't. The underlying road attributes are not exposed to you.

## The dangerous pattern

<Warning>
  Server-side truck routing with constraints, device-side recalculation **without** them.

  The driver deviates. The phone reroutes. The constraint set never left your backend.

  **Push vehicle profiles to the device. Test the recalculation path.**
</Warning>

## Related

<CardGroup cols={2}>
  <Card title="Truck Routing" href="/guides/truck-routing">
    Constraints, units, and validating they apply.
  </Card>

  <Card title="Calculate a Truck Route" href="/examples/truck-route">
    Working code, with CI assertions.
  </Card>

  <Card title="Fleet Routing" href="/use-cases/fleet-routing">
    Where the profile lives, and how it reaches the device.
  </Card>

  <Card title="HERE vs TomTom" href="/comparisons/here-vs-tomtom">
    The axle-group difference, sourced.
  </Card>
</CardGroup>

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

***

Need production HERE API keys or implementation support? Placematic is an official HERE Technologies reseller and implementation partner. We have deployed HERE truck routing into production ELD systems. [Talk to us](https://placematic.com/contact/).