The ring road (Route 4169) and driving on Samui

Summary

One main road, Route 4169, loops about 50-51 km around Koh Samui and links all the main beach towns. Driving is on the left. A non-stop lap takes about 1.5-2 hours; with beach and viewpoint stops it makes a relaxed half or full day.

Details

Route 4169 (ring road)

The ring road circles the island through Nathon, Maenam, Bophut, the airport turn, Chaweng and Lamai - about 50-51 km according to OpenStreetMap-based and local 2026 sources (some guides say 51-60 km with detours). Non-stop driving time is about 90 minutes; the east and north sections are well-paved two-lane road.

Side roads

Route 4171 branches off in the north-east (Bang Rak, Plai Laem, Choeng Mon) and Route 4170 covers the south-west (Taling Ngam, Thong Krut, Lipa Noi). The 4170 is narrower, steep and sandy-asphalt in places, and becomes slippery quickly in rain. Some interior roads (e.g. the last stretch to the Secret Buddha Garden) are steep enough to need high clearance or 4WD.

Traffic

The Chaweng-Lamai stretch clogs on late afternoons and in peak season (December-February) - allow an extra 20-30 minutes. Nathon, Chaweng and Lamai have the most fuel stations.

Driving side

Thailand drives on the LEFT.

Weather note

Samui's wettest months are roughly October to December (reversed compared with Phuket/Andaman coast). Painted lines and bends get slick fast in rain.

Local tips

• Stay on the ring road and you cannot really get lost - a wrong turn just means a longer lap.
• Ride/drive clockwise to finish on the west coast for sunset; go early to beat Chaweng traffic.
• Police checkpoints (licence/IDP/helmet) operate near Chaweng and the airport.
• Fuel for a full scooter lap is well under a tank; top up in Nathon or Lamai.

Safety

• The hills between Chaweng and Lamai and the south-west coast descents are the main accident spots - slow down, especially when wet.
• Wear a helmet on any two-wheeler; it is the law for driver and passenger.
• Avoid riding/driving rural stretches at night and never after drinking.

Frequently asked questions

How long is the ring road around Koh Samui?

About 50-51 km for the main Route 4169 loop (up to ~60 km with beach detours).

How long does it take to drive around Koh Samui?

About 1.5-2 hours non-stop; 4-6 hours with beach, temple and viewpoint stops.

Which side of the road do you drive on in Koh Samui?

The left side, as in the rest of Thailand.

Is the Koh Samui ring road safe for scooters?

The north and east sections are easy and flat. The south and west sections have steep hills, sharp corners and slippery patches in rain - ride within your skill and slow down when wet.