R-305
No Passing
In addition to the general passing rules, prohibits all vehicles 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" or "End of prohibitions" sign. Where passing is already prohibited by rule, it serves as a general reminder of that prohibition.
Category: Other prohibition and restriction signs
Source: General Traffic Regulations (RD 1428/2003), Annex I; designs per the official sign catalog (RD 465/2025)