Road sign R-300: Minimum following distance

What it means

«Prohibición de circular sin mantener con el vehículo precedente una separación igual o mayor a la indicada en la señal, excepto cuando se vaya a efectuar la maniobra de adelantamiento. […]» RD 465/2025, Annex I of the RGC (BOE-A-2025-12199), Spanish original.

It sets a minimum distance, in metres, to the vehicle ahead, except when you are about to overtake. If it carries no figure, it merely recalls the safety distance the regulation already sets.

Where you meet it

You see it on the stretch where that gap is required. With a figure, it bans driving closer than those metres, except to overtake; with no figure, it recalls the general rule of article 54.

What you must do

Keep the gap the sign shows; with no figure, apply the general rule: be able to stop without colliding.

Details that count

As a general rule, the gap must allow the driver to stop without colliding if the vehicle ahead brakes, taking account of speed, grip and braking. When following another vehicle without signalling an intention to overtake, drivers must also leave room so the vehicle behind can overtake them safely: at least 50 m if the maximum authorised mass exceeds 3,500 kg or the vehicle or combination exceeds 10 m in total length. This additional duty does not apply in built-up areas, where overtaking is prohibited, with more than one lane in the same direction, or when traffic is too congested to allow overtaking. Bicycles riding in a group are exempt from these gaps between themselves, taking extra care to avoid rear-end collisions. For other drivers, the exceptions do not remove the gap needed to avoid a collision (RGC art. 54.1, 54.2 and 54.3).

What it is confused with

It is confused with the safety distance in a tunnel (sign S-5): when not intending to overtake, the minimum gap is 100 m or 4 seconds. For vehicles with a maximum authorised mass over 3,500 kg, it is 150 m or 6 seconds (RGC arts. 95.6 and 54). R-300 is something else: a regulation sign that carries its own figure or, without one, recalls the general rule.

Related signs

• R-305: No overtaking
• S-5: Tunnel
• R-306: No overtaking for lorries

Studied in topic 15: Speed.

Source: RGC arts. 54.1, 54.2, 54.3, 95.6; RGC Annex I, sign R-300 (RD 465/2025).