Road sign R-400a: Mandatory direction (arrow to the right)

What it means

«La flecha señala la dirección y sentido que los vehículos tienen la obligación de seguir.» RD 465/2025, Annex I of the RGC (BOE-A-2025-12199), Spanish original.

The sign is a mandatory one: the arrow shows the direction and way that vehicles are obliged to follow. It does not advise, it orders. R-400a is the one with the arrow pointing right.

Where you meet it

You see it at a junction, at the point where you must take that direction. It is one of five versions (a to e) with the same official name; the letter tells which way the arrow points.

What you must do

If you meant to go straight on and reach a junction with this sign, you must take the arrow's direction: it marks the only direction and way you must follow at that point, with no room for your own judgement. And obey even if the layout of the road seems to contradict it (RGC art. 132.2).

Details that count

Mandatory direction imposes the general direction vehicles must follow at that point; the mandatory-passing sign, R-401, has a narrower function: showing the side of a refuge or obstacle on which you must pass (RGC art. 145.2.e). These are mandatory signs, the class that imposes a compulsory rule of traffic. It belongs to the class of mandatory signs: the arrow does not advise, it orders (RGC art. 145.2.e).

What it is confused with

It is confused with R-402, «Mandatory direction at a roundabout». The mandatory-direction arrow marks a specific turn at that point; the roundabout sign marks the rotation direction you must follow within it, a continuous movement. It also resembles R-400c: the same sign, another arrow.

Related signs

• R-400c: Mandatory direction (arrow straight ahead)
• R-402: Mandatory direction at a roundabout
• R-304: No U-turn

Studied in topic 10: Vertical road signs.

Source: RGC arts. 132.2, 145.2.e; RGC Annex I, sign R-400a (RD 465/2025).