Costa Rica Tyre Rules 2026: RTV Check, 1.6 mm Tread

Costa Rica carries traffic over Cerro de la Muerte at roughly 3,335 metres, a stretch of the Interamericana Sur where cloud sits on the road, rain drives sideways and night temperatures reach single figures or lower. It is one of the coldest public roads in Central America — and there is still no winter tyre rule, no marking requirement and no stud regime anywhere in Costa Rican law.

The tyre standard here is a condition standard. Tread floor is 1.6 mm in the main grooves, per Council Directive 89/459/EEC, and tyre condition is examined at the periodic RTV roadworthiness inspection.

Tyre Law Summary for Costa Rica

Condition, not season

Costa Rica regulates tyres the way it regulates the rest of the vehicle: through a periodic test. The RTV looks at whether the tyre is damaged, whether it is worn out, and whether what is fitted across an axle matches. There is no snowflake symbol to satisfy and no calendar window to track.

That puts the burden on the driver rather than on a date. A tyre that is legal in March is not automatically fit for the October rains on the Pacific slope.

The green season

Costa Rica’s wet season — the invierno or green season — runs roughly May to November on the Pacific side, with September and October usually the heaviest. The Caribbean slope runs its own pattern and can be wet at any point in the year.

What it does to roads:

• Unpaved access roads degrade fast. The routes into Nosara, Santa Teresa, parts of Nicoya and the older approaches to Monteverde turn from washboard to rut within days of sustained rain.
• Rivers rise. Low crossings that are trivially passable in the dry months become genuine hazards. That is a judgement call about depth and current, and no tyre changes the answer.
• Mountain roads drain across the surface. On the Interamericana Sur and the Braulio Carrillo route, water sheets over the carriageway, and groove depth is the only thing that clears it.

Altitude and temperature

The Central Valley sits at around 1,200 metres, Cerro de la Muerte at more than 3,300. Tyre pressures set at sea level will read differently once you have climbed, so reset them cold at your base rather than carrying a coastal figure into the mountains.

Cold and fog on the high sections mean lower grip than the same road offers on a clear afternoon. A normal all-season or summer tyre is entirely adequate there — but a worn one is not, and that is where the risk actually sits.

Costa Rica’s two borders

• Nicaragua: to the north, crossings at Peñas Blancas and Los Chiles. No winter tyre season.
• Panama: to the southeast, crossings at Paso Canoas and Sixaola. No winter tyre season.

Those are the only land frontiers. Guatemala and Honduras are sometimes grouped with them but lie several countries north, beyond Nicaragua, and reaching either by road is a multi-border drive.

Speed limits, fines and mandatory equipment are set out in the Driving in Costa Rica guide.