Definitions and trigger criteria:
A transport is considered "exceptional" as soon as one of the standard criteria for size or weight is exceeded.
• Length: > 16.50 m — or even > 20 m depending on the category.
• Width: > 2.55 m
• Weight / GVW / GCW is significant, or the combination exceeds 44 tons (or depending on configuration).
• It may involve indivisible goods, special equipment, oversized materials, etc.
Depending on the characteristics, the transport can be classified into 1st, 2nd, or 3rd category of exceptional convoy.
Procedure based on the category:
• 1st category ("slightly out of standards")
• If the convoy slightly exceeds the standard limits but remains moderate, a simple prior declaration is sufficient.
• This declaration can be made online via the official "Mon transport exceptionnel" service.
• If online access is unavailable, the paper form (CERFA) can be filled out and sent by mail.
• Once the declaration is validated, the carrier receives an acknowledgment of authorization (often called APL — Local Scope Authorization). This acknowledgment allows circulation for a maximum duration of 3 years.
• 2nd or 3rd category (truly out-of-standard convoy)
• In these cases, an individual authorization is required.
• The request must be made via "Mon transport exceptionnel", or by paper form (CERFA n° 15625*03).
• The authorization must be sent to the prefecture of the departure department (or the entry department in France if the convoy comes from abroad).
• All necessary information must be included: description of the convoy (vehicle(s), trailer(s), load), dimensions and weight, proposed itinerary, dates and times, possibly a plan / diagram of the convoy, etc.
Where to submit the request:
• Through the online service "Mon transport exceptionnel" — standard procedure since 2023.
• By mail (CERFA form) to the prefecture of the relevant department (departure or entry).
Instructions & prior checks:
Before the transport, it is necessary to:
• Check the itinerary: via the official map portal for roads authorized for convoys (e.g., via Géoportail TE).
• Examine the heights, bridges, passages, potential construction sites, to ensure the convoy can pass.
• Adhere to legal deadlines: the authorization must cover the entire journey, and the request must often be made several days in advance.
Circulation rules after authorization:
Once the authorization is granted:
• The convoy must display the "EXCEPTIONAL CONVOY" signage.
• Reduced speed limits, depending on the road / type of convoy.
• Minimum distance between convoys, lighting, signage for overhangs, markings, possibly escort or guidance depending on the case.
• Certain restricted periods: from Saturday noon (or the day before a holiday) to Monday at 6 a.m., public holidays, or unfavorable weather conditions — unless an exemption is granted.
In practice — steps to follow:
- Assess the convoy: dimensions, weight, type of load.
- Determine the category (1st / 2nd / 3rd).
- For category 1: make the prior declaration via "Mon transport exceptionnel" or the paper form.
- For category 2 or 3: complete the individual authorization request, send it to the competent prefecture.
- Attach all supporting documents (vehicle, trailer, load, itinerary, etc.).
- Once the authorization is received: prepare the convoy (signage, coupling, itinerary, escort if necessary).
- Travel while adhering to prescriptions, schedules, limitations, and keep the authorization available.