ADR European Road Transport: A Beginner's Guide

ADR is the Accord européen relatif au transport international des marchandises Dangereuses par Route — the European Agreement concerning the International Carriage of Dangerous Goods by Road. It is a UN treaty administered by UNECE in Geneva, originally signed in 1957, and updated on a two-year cycle. ADR 2025 is the current edition for 2025–2026; ADR 2027 will follow.

Who is bound by ADR

53 contracting parties as of 2026, covering essentially all of Europe plus several Central Asian and North African states. Each party transposes ADR into national law, so a shipment from Rotterdam to Athens transits multiple legal regimes that all enforce essentially the same text.

Structure of ADR

Annex A — General provisions and provisions concerning the dangerous substances and articles. Parts 1–7.
Annex B — Provisions concerning transport equipment and transport operations. Parts 8 and 9.

Part 3 contains the Dangerous Goods List and special provisions. Parts 4 and 6 cover packaging and tank construction. Part 5 covers consignment procedures (marks, labels, documents, placards). Parts 8 and 9 are the driver / vehicle / operational provisions.

Transport categories and the 1,000-point rule

Section 1.1.3.6 of ADR introduces transport categories 0–4. Each substance has a category, and each category has a "value" per kg (or per litre). The total points carried on a transport unit cannot exceed 1,000 if the consignor wants to use the partial exemption that relaxes most ADR requirements (no orange plates, no driver ADR certificate, no tunnel restrictions).

Category 0 — most dangerous (explosives 1.1A, etc.) — multiplier 0, meaning even a single kg breaks the exemption.
Category 1 — multiplier 50.
Category 2 — multiplier 3.
Category 3 — multiplier 1.
Category 4 — multiplier 0 (i.e. no contribution to the limit).

A transport carrying 200 L of UN1203 petrol (Cat 2, multiplier 3) is at 600 points and still under the limit. Add a single 25 L jerry can of UN1230 methanol (Cat 2 again) and you reach 675 points; you are still exempted under 1.1.3.6 but only just.

Tunnel restriction codes

Each fully regulated entry in the DGL has a tunnel restriction code from B to E. Tunnels are categorised A through E by their operator; a vehicle carrying goods restricted to category E may not enter a category A tunnel. The Mont Blanc and Fréjus tunnels are notoriously strict.

Documents the driver carries

Transport document (consignment note) per 5.4.1.
Instructions in writing (the "tremcards") in a language the driver understands and in the language of every state of transit.
Driver's ADR training certificate per 8.2.1.
Vehicle approval certificate (for tank, MEMU, EX/II, EX/III, FL, OX, AT vehicles).
Photo ID for each crew member.
Container packing certificate where applicable for multimodal transport.

Vehicle marking and equipment

Orange plates front and rear (40 × 30 cm) bearing the Hazard Identification Number (HIN/Kemler code) and UN number for tank / bulk transport. Placards on the sides and rear for relevant hazard classes. The vehicle's standard equipment includes wheel chock, two warning signs, eye rinsing liquid, hi-vis jacket per crew member, hand torch, gloves, and goggles. Class-specific equipment (sand bucket, drain seal) may also be required.

The Safety Adviser (DGSA)

Every undertaking that consigns, packs, loads, fills or unloads dangerous goods by road must appoint a Dangerous Goods Safety Adviser per Chapter 1.8.3, certified by examination, with annual reporting obligations. There are narrow exemptions for very small operations.

How ADR connects to other modes

Shipments routinely move ADR road → IMDG sea → ADR road again. The UN numbers, classes and packing groups are identical, but the documentation, marking and crew training rules change at each modal boundary. For the sea leg see the IMDG quick reference; for an overview of how the system fits together start with the complete guide to UN numbers and hazard classes.