# Tunnel Restriction Code

*Last updated: 2026-06-26*

> Dangerous goods safety advisors and transport planners check Tunnel Restriction Codes before finalising any hazardous goods route.

Dangerous goods safety advisors and transport planners check Tunnel Restriction Codes before finalising any hazardous goods route. Under the ADR framework, each road tunnel is assigned a category from A to E that determines which classes of hazardous materials may pass through – ranging from unrestricted access at Category A to a near-total ban on explosives and highly flammable substances at Category E. The more restrictive the code, the more cargo categories must be diverted to alternative roads. Verifying these codes along the planned itinerary is a binding obligation for the carrier, dispatcher, and consignor alike. Tunnel Restriction Codes are distinct from general weight or dimensional restrictions, which apply regardless of hazardous goods classification.

**Source:** [https://unece.org/transport/dangerous-goods](https://unece.org/transport/dangerous-goods)

## Quick Facts

| Property | Value |
|---|---|
| Term | Tunnel Restriction Code |
| Language | EN |
| Word count | 114 |
| Last updated | 2026-06-26 |
| Source | https://unece.org/transport/dangerous-goods |

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