1. Definition and legal scope
• Exceptional transport (exceptional convoy): circulation of a vehicle or convoy whose dimensions (length, width, height) or mass exceed the limits authorized by the Highway Code or the regulations in force, requiring a special authorization and accompanying measures.
2. Key texts and official references (main list)
- Code de la Route, general applicable provisions (limits, circulation, liability). (see Legifrance). (Légifrance
- Arrêté of 4 May 2006 relating to exceptional transports (authorization procedures, convoy leader, escort obligations, documents to be provided). — fundamental text for the examination of authorization requests. Légifrance
- Previous orders and amendments (e.g. order of 26 November 2003 and other regional clarifications) — useful for historical context and certain transitional regimes. Légifrance
- Ministerial circulars and technical guides (prefectures, departmental directorates) and Petitioner user manual published by road safety / Ministry (practical procedures and templates). Sécurité Routière
- CEREMA technical guides (crossing of engineering structures, passage of structures, route dimensioning) — essential for route studies and verification of engineering structures. PILES
These texts constitute the legal basis; administrative authorization and local measures (for structure crossings, departmental conditions) are based on them. Légifrance
3. Categorization of exceptional transports (practical rules & thresholds)
Regulations distinguish three categories according to dimensions/mass — each category implies distinct authorization formalities and conditions. Usual thresholds (summary table):
• 1st category : length ≈ 16.6–20 m, width ≈ 2.6–3 m, mass ≈ 44–48 t.
• 2nd category : length ≈ 20–25 m, width ≈ 3–4 m, mass > 48 t (and depending on axles).
• 3rd category : beyond these values (very exceptional).
(Refer to the detailed tables and definitions published by State services and the ministerial guide for category classification). Entreprendre Service Public
Note: the most constraining characteristic (e.g. very large width or very high mass) determines the convoy category and therefore the prescriptions and authorization required.
4. Authorizations: types, procedure and required documents
- Types of authorizations
• Individual authorization (nominative): issued for one route, a duration or a limited number of trips (e.g. one-off transport).
• General or permanent authorization (if provided locally): for certain regular routes if local regulations allow it (but individual authorization often remains the rule). Sécurité Routière
- Types of authorizations
- Competent authority
• Prefecture of the department of departure / of the transport operator’s registered office depending on the case: examination and issuance. Certain escort missions may be organized by departmental services. Sécurité Routière - Documents to be provided (frequent requirements)
• Complete description of the convoy (tractor unit, semi-trailer, overall dimensions, total mass, axle load distribution). Légifrance
• Vehicle technical data sheet (elements necessary for examination). Légifrance
• Detailed route, loading plans, securing measures, passage studies (structures crossed), schedule and proposed circulation times. Sécurité Routière
• Insurance certificates, certificates of conformity for load securing equipment and, if necessary, calculation notes (bridges/structures). PILES - Deadlines and conditions
• The administration may impose conditions: restricted circulation hours, escort (police/gendarmerie and/or private escort), detours, signage, piloting, traffic management. Légifrance
5. Technical rules relating to mass, axles and dimensions
• Standard national limits (non-exceptional transport): total weight and axle loads set by the Highway Code; beyond these limits, an exceptional transport authorization is required. (see texts on weight and distribution). Légifrance
• Axle loads and distribution: load distribution over axles determines acceptability and impact on infrastructure (roadway, bridges). Departmental services/CEREMA assess routes accordingly. PILES
• Height: specific obligation for any height > 4 m (verification of engineering structures, special constraints).
6. Engineering structures (bridges, tunnels) — route study and liability
• Preliminary study is mandatory if the convoy crosses engineering structures: load calculations, verification of load-bearing capacities, clearances and, if necessary, calculation notes by an engineering firm. CEREMA publishes technical guides and methods for crossing engineering structures. PILES
• Transport operator liability for passage safety; the prefectural authority may impose alternative routes or local reinforcements. Bulletin Officiel
7. Load securing and safety, applicable standards
Load securing rules are critical: defective securing = criminal, civil and administrative risk.
• NF EN 12195-1 — calculation methods and securing devices (main requirements relating to securing forces, safety coefficients, equipment). Standard to be purchased via AFNOR (summaries available in guides). AFNOR Boutique
• NF EN 12642 (Code XL), reinforced bodies; when the body is Code XL certified and the load compliant, securing may be reduced. INRS
• NF EN 12640 — lashing points and devices for securing loads on vehicles. ASNR
• Practical guides: INRS, construction safety, departmental guides explain implementation (choice of straps, force calculations, edge protection, compatibility of devices). INRS
Practical recommendation: keep load securing calculation sheets and equipment certificates, often required during inspections.
8. Escort, convoy leader, signage and road safety
• Convoy leader: person responsible during circulation (must speak/read French or be accompanied by a translator if necessary). Bulletin Officiel
• Escorts: depending on category and prefecture, accompaniment by public forces or private escorts; signage obligations (“exceptional convoy” signs, lights, beacons according to prescriptions). Légifrance
• Signage and marking: regulatory signs, night marking, lighting if necessary. The administration may impose additional measures (slowdowns, temporary closures). Sécurité Routière
9. Inspections and penalties
• Roadside inspections by law enforcement and departmental services: verification of authorization, dimensional compliance, load securing, insurance. Non-compliance = fine, immobilization of the convoy, civil/criminal liability in case of accident.
10. Standard documents / checklist to prepare for the authorization request
- Request form (prefecture / petitioner manual).
- Vehicle and load plans (precise overall dimensions).
- Detailed route note + map/km references + alternatives.
- Certificates and technical sheets: vehicle, insurance certificate, load securing equipment (NF EN).
- Engineering structure crossing study (if required).
11. Recommended standards, guides and technical documents.
• NF EN 12195-1 — load securing (AFNOR). AFNOR Boutique
• NF EN 12642 (Code XL) — bodies (AFNOR / INRS for interpretation). INRS
• NF EN 12640 — lashing points. ASNR
• INRS, CEREMA guides — load securing, routes, structure crossings. INRS
• IRU code of best practices / international rules for load securing. IRU
- Resources and useful links (selection)
• Legifrance — Arrêté of 4 May 2006 (exceptional transport): official text. Légifrance
• Service-public / Practical sheet exceptional transport (categories and formalities). Entreprendre Service Public
• Petitioner user manual (Road safety / ministry): practical procedures and templates. Sécurité Routière
• CEREMA — Engineering structure crossing guide (PDF): route study and technical methods. PILES
• INRS — Load securing (PDF guide): best practices and NF EN references. INRS
• AFNOR — NF EN 12195, 12642, 12640 standards sheets (paid access). AFNOR Boutique
14. Legal notes and final recommendations
• Liability: the transport operator and the convoy leader assume civil and criminal liability in the event of an accident resulting from an authorization request or defective load securing — keep evidence and calculations.
• Regulatory updates: regulations may evolve; check departmental orders and local circulars before each operation.
• Standards: purchasing AFNOR standards is recommended to obtain full requirements (NF EN 12195-1, NF EN 12642, NF EN 12640). INRS / CEREMA guides provide practical applications.