https://www.boe.es/boe/dias/2012/02/04/pdfs/BOE-A-2012-1677.pdf
Hazardous Goods:
B.2.1 Vehicles required to display the orange warning panels according to the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR), on Sundays and public holidays within the corresponding territorial scope – national or regional -, from eight to twenty-four hours, and on the eve of these holidays, not Saturdays, from thirteen to twenty-four hours, as well as on the days and hours indicated in Annex VI.
In the event of several consecutive public holidays, including Sundays, within the corresponding territorial scope, the restrictions will only apply on the first of them from eight to fifteen hours, and on the last one corresponding to Sunday or a public holiday, leaving the rest of the public holidays unrestricted.
All this without prejudice to the temporary restrictions that may be imposed on local festive occasions.
B.2.2 In accordance with Article 5 of Royal Decree 551/2006, of May 5, regulating the operations of hazardous goods transportation by road in Spanish territory, the itineraries to be used by vehicles for the transportation of hazardous goods shall be as follows:
For distribution and delivery movements: The movements aimed at distributing and delivering the hazardous goods to their final recipients or consumers shall use the most suitable itinerary, both in terms of road safety and traffic flow, covering the minimum distance possible along conventional roads to the point of delivery of the goods. Circumferential routes, variants, or outer loops around population centers must be used unconditionally if available, and if there is more than one, the outermost route around the population center shall be used, entering the urban area only to carry out loading and unloading operations, and always using the access closest to the delivery point unless there are justified reasons of force majeure.
For other types of movements: If the points of origin and destination of the movement are included in the RIMP – Network of Itineraries for Hazardous Goods – listed in Annex IV of this Resolution, the vehicles transporting them must use them obligatorily on their route. If one or both of these points are outside the RIMP, the movements must be made on conventional roads that allow access to said Network through the nearest entry or exit in the direction of travel, in order to ensure that the route on single-carriageway roads is as short as possible.
Traffic on routes other than those indicated here shall require that the route does not pass through or only does so through the least dangerous crossroads – in accordance with the traffic intensity, classification, and distribution, the size of the urban center, urban configuration, and layout and regulation thereof -, and also, prior notification at least twenty-four hours in advance to the Traffic Unit of the Civil Guard Traffic Group of the corresponding province, who will confirm, if applicable, the use of the new route.
Likewise, vehicles may leave the RIMP on those journeys whose destination or origin is the driver’s habitual residence – for daily or weekly rest periods – or for vehicle repair or maintenance operations, provided that, in any case, the parking conditions specified in the ADR are met.
The provisions of the preceding paragraphs shall not apply when the transportation of such goods is carried out in accordance with any of the exemptions provided for in the ADR by reason of the cargo, quantity, or type of transport.
B.2.3 Vehicles transporting the materials referred to in Annex III of this Resolution, under the conditions specified therein, are exempt from the prohibitions established in sections B.2.1 and B.2.2.
B.2.4 The circulation of vehicles covered in this section B.2 on the sections included in Annex V of this Resolution may only be carried out on the days and during the time periods indicated therein.