R-306
No passing for trucks
Prohibits trucks whose authorized mass exceeds 3,500 kilograms from passing motor vehicles on the roadway, except two-wheeled motorcycles, provided they do not enter the part of the road reserved for oncoming traffic. It applies from where the sign is placed until the next "End of no passing for trucks" or "End of prohibitions" sign.
Category: Other prohibition and restriction signs
Source: General Traffic Regulations (RD 1428/2003), Annex I; designs per the official sign catalog (RD 465/2025)