Skip to main content

​
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
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.

​
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.
Verified against the Matrix Routing v8 OpenAPI specification, v8.47.0, July 2026.
Physical constraints still apply. A hazmat tanker is also a tall, heavy vehicle. Both constraint sets are required.

​
Do not map a boolean

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.

​
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.
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.

​
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

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

​
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.

Hazmat Routing

The full architecture, and refusing to route.

Truck Routing

Physical constraints, which also apply.

ELD Platform

Map release versioning as an audit artifact.

HERE vs TomTom

Both implement ADR tunnel codes. The taxonomies differ.
HERE documentation: Routing API v8 reference
Need production HERE API keys or implementation support? Placematic is an official HERE Technologies reseller and implementation partner. Talk to us.