Guide: Koh Rong to Rayong Road Trip Stops & Drive

Koh Rong, Cambodia's second-largest island, sits at 10°43′N 103°14′E, about 25 km off Sihanoukville. Rayong, Thailand, a province on the Gulf of Thailand coast, lies roughly 300 km northwest as the crow flies. The overland journey connects two worlds: the island's quiet beaches and the mainland's industrial and agricultural heart. The route typically involves a ferry to Sihanoukville, then highway driving through Cambodia and Thailand, crossing at the Ban Hat Lek–Cham Yeam border.

This guide covers distance, driving time, fuel costs, and notable stops, ensuring you have a practical plan. For broader tips on discovering unusual attractions, see our guide on how to find the best stops and hidden gems between cities.

Total driving distance is approximately 415 km, with a realistic driving time of 7–8.5 hours excluding ferry and border stops.

Road quality varies: Cambodian NH4 is generally good but lacks guardrails at curves; Thai Route 3 is excellent with clear signage. Drive defensively, especially near Rayong where industrial trucks are common. The speed limit in Cambodia is 80 km/h on highways, but expect slower speeds due to motorcycles and bicycles. In Thailand, limit is 80–90 km/h on rural roads, and speeding is strictly enforced.

For families with children, this trip is feasible, but plan stops every 2 hours at fuel stations that often have clean restrooms. In Cambodia, the Star Mart fuel stations along NH4 are reliable; in Thailand, PTT and Shell stations offer food courts and convenience stores. For pet owners, driving with pets is allowed, but note that crossing international borders requires a health certificate and vaccination record. Most hotels along the route accept pets, but confirm in advance.

To manage fatigue, the journey is lengthy; be sure to rest at designated points. Consider an overnight stop at Trat, allowing time to visit the town's market and enjoy the nearby beaches. The drive from Sihanoukville to Koh Kong is particularly winding; avoid driving at dusk due to wildlife crossing.

• Rest zones: Sihanoukville (start), Koh Kong (border), Trat (halfway), and Rayong (end).
• Checkpoints: expect two Cambodian police checks (NH4) and occasional Thai weigh stations.
• Medical: The first hospital is in Sihanoukville; on the Thai side, Trat Hospital is well-equipped.

Overall, it is worth driving Koh Rong to Rayong? If you enjoy varied landscapes and cultural transitions, yes—but at least 2 days are needed. For those prioritizing speed, flights and ferries exist but complicate the trip. Ultimately, the journey offers a unique window into both countries' everyday life.

Leaving Sihanoukville, the Cardamom Mountains dominate the horizon, a largely pristine rainforest range. This area is part of the Indo-Burma biodiversity hotspot, and you may spot gibbons or hornbills near roadside viewing points. The drive along NH4 offers occasional viewpoints where you can see tropical forests and rubber plantations. As you approach the border, the average temperature is 27°C year-round, with a wet season from May to October that can create washed-out road edges but also lush waterfalls.

On the Thai side, the landscape flattens into orchards and rice paddies, particularly around Trat. This province is Thailand's largest producer of rubber and also known for its fruit. Near Rayong, pineapple plantations and durian farms line the road, especially along the "Sukhumvit Orchards" section. Local commerce thrives at roadside stalls that sell fresh produce, and the best stops Koh Rong to Rayong often include such farms where you can buy directly.

In Trat city, the weekly Walking Street market (Saturday evenings) offers a taste of local street food, such as som tam and grilled seafood. On the Cambodian side near Koh Kong, small villages sell grilled squid and prahok (fermented fish paste), reflecting seafood heritage. The interplay between Khmer and Thai cultures is fascinating: near the border, bilingual signage and mixed architecture are common.

For an off-the-beaten-path break, consider the Klong Ya water buffalo farm just east of Trat, where you can feed the animals—but verify current opening hours as they vary. Alternatively, the Nam Tok Khlong Kaeo waterfall, 14 km south of Trat, is a hidden gem for a picnic, though access roads are uneven.

The journey begins with a ferry from Koh Rong to Sihanoukville (about 45 minutes, fares vary from $12 to $25 depending on operator). From Sihanoukville, National Road 4 (NH4) heads northeast to Phnom Penh, but you'll turn west at the junction for Koh Kong. The border at Cham Yeam (Cambodia) and Hat Lek (Thailand) is open daily from 6 AM to 10 PM. Ensure your vehicle has proper insurance and bring vehicle export papers if crossing in your own car; otherwise, many travelers opt to rent a car on each side to avoid paperwork.

Fuel stops are frequent along NH4, with prices around $1.10 per liter in Cambodia and about ฿30 (roughly $0.85) in Thailand. Border crossing fees are about $5 per person for visa on arrival (if needed) and a small fee for vehicle entry (around $10). Plan for a total fuel cost of about $45–60 for the whole drive, depending on your vehicle's efficiency.

The Thai road system is well-maintained; Route 3 (Sukhumvit) is dual carriageway for most stretches. However, be aware of industrial traffic near Rayong, as it is a hub for petrochemical plants. In contrast, Cambodian roads, especially near Koh Kong, are narrower and less predictable, with some sections in need of repair. The border area has a few typical amenities: money changers, small eateries, and duty-free shops.

• Ferry: Sihanoukville Express (fast) vs. local boats (slow).
• Border crossing: Prepare USD for Cambodia, Thai baht for Thailand.
• Cambodia side: NH4 is two-lane, with occasional overtaking lanes.
• Thailand side: Route 3 is fully paved with signposted exits.