Driving in Southern Thailand: What the Roads Are Like

Southern Thailand is a long narrow peninsula with a coast on each side, and driving it is mostly a question of choosing which coast you are on and when. The roads themselves are good: the trunk routes are four-lane divided highways in decent condition, distances between towns are short by Thai standards, and there are no mountain passes to compare with the north. What shapes a southern itinerary instead is weather that arrives on the two coasts at different times of year, a great deal of heavy plantation traffic, and the ferry timetables that stand between you and most of the islands.

The one thing worth knowing before you plan anything: the far southern provinces on the Malaysian border carry travel advisories from several governments, and that genuinely does affect route choice at the bottom of the peninsula. Everything else in the south is normal holiday driving.

• Main routesHighway 4 down the Andaman side, Highway 41 down the middle
• Andaman wet seasonRoughly May to October
• Gulf wet seasonRoughly October to January
• Islands reachable by roadPhuket and Koh Lanta; the rest need a ferry

One narrow country, two coasts

North of Surat Thani the country is genuinely thin — at Kra Buri in Ranong it narrows to a few tens of kilometres between the Andaman Sea and the Burmese border — and the road network reflects that. There is essentially one route through the isthmus, and it is Highway 4.

South of Chumphon the peninsula widens and splits into two corridors. Highway 4 swings west to Ranong and runs down the Andaman side through Khao Lak, Phang Nga, Krabi and Trang. Highway 41 carries on down the middle through Surat Thani, Nakhon Si Thammarat and Phatthalung, where the two rejoin. Highway 41 is faster; Highway 4 is far better looking.

The two monsoons

This is the fact that determines when to drive where. The Andaman coast — Ranong, Khao Lak, Phuket, Krabi — takes the southwest monsoon and is wettest from roughly May to October. The gulf coast — Surat Thani, Samui, Nakhon Si Thammarat — takes the northeast monsoon and is wettest from roughly October into January. They do not coincide, which is why there is no genuinely bad time to visit the south as a whole, only a bad time to visit one side of it.

Rain here is not drizzle. It arrives as a wall, drops visibility to a few car lengths, floods the drains within minutes and leaves standing water in the wheel ruts of every highway. The recovery is quick — an hour later the road is steaming and dry — but the half hour in the middle is not a time to be overtaking a lorry. See the rainy season and flooded roads, and on two wheels, riding in tropical rain.

What the traffic is like

Southern highway traffic is dominated by plantation freight. Rubber and palm oil are the region's industries, and that means loaded lorries on every road: latex tankers, flatbeds stacked with oil-palm fruit bunches, timber, and pickups converted into something considerably heavier than a pickup. They are slow uphill, they do not stop quickly, and they shed debris.

In the towns, the local hazard is the songthaew — the converted pickup with bench seats that serves as a bus, stopping anywhere, without warning, usually in the left lane. How songthaews stop is worth reading before you drive in Krabi or on Phuket.

On the coast roads, watch the surface itself. Wind-blown sand across the tarmac near beaches, and gravel washed out of side tracks after rain, both catch riders on corners. Sand and gravel on Thailand's coastal roads covers the technique.

Islands and ferries

Two southern islands can be reached without a boat. Phuket is joined to the mainland at the Sarasin Bridge on Highway 402, which is why so many road trips start there — see Phuket to Khao Lak and Khao Sok. Koh Lanta Yai is reached by the Siri Lanta Bridge from Koh Lanta Noi, but Lanta Noi itself is still reached by a short vehicle ferry from the mainland at Ban Hua Hin, so the crossing has not gone away entirely.

Everything else — Samui, Phangan, Tao, the Trang islands, Phi Phi — needs a boat, and only some of those boats take vehicles. Which islands you can drive to and how the loading works is set out in taking a car or motorbike on a Thai island ferry, and the practicalities of the two main crossings in the Koh Chang and Koh Samui vehicle ferries.

Phuket is the hard part

Nothing else in the south drives like Phuket. It is a small island with a large population, steep hills between the beaches, an infamous descent into Patong, heavy tourist traffic and a crash record that stands out even by Thai standards. If you are working up to southern driving, do the mainland first. Driving in Phuket sets out what makes it different.

The far south

Below Hat Yai the peninsula runs into the provinces covered by long-standing travel advisories: Pattani, Yala and Narathiwat, plus named districts of Songkhla. This affects which roads you would sensibly use to reach the Malaysian border and which you would not. It is a subject that deserves accuracy rather than drama, and it is handled in driving in the deep south: what the advice says and in crossing into Malaysia by road.

Frequently asked questions