Cambodia Driving Rules for Americans (2026)
Cambodia drives on the RIGHT, like the US. Urban speed limits are ~40 km/h and highways ~90–100 km/h. The most enforced rules for tourists are helmets, licenses, and speed. Foreigners should carry an IDP — it's officially required and defuses roadside stops.
Written and posted rules exist, but real-world driving is chaotic and lightly policed. Defensive driving matters more than the letter of the law.
Which Side of the Road? (Right — Same as the US)
Good news for American drivers: Cambodia drives on the right-hand side, exactly like the United States. The steering wheel is on the left, you overtake on the left, and roundabouts flow counter-clockwise. That removes the single biggest adjustment US visitors face in places like Thailand or the UK.
The catch is not the side of the road but the discipline on it. Lane markings are treated as suggestions, motorbikes flow around cars like water, and vehicles routinely drift into oncoming lanes to overtake. You'll adapt to the direction instantly; adapting to the chaos takes longer.
Quirk to know: It is legal and common for small motorbikes to keep right and for larger vehicles to pass them widely. Expect two-wheelers on the shoulder, between lanes, and occasionally coming toward you against traffic.
Speed Limits in Cambodia
Limits are posted in kilometers per hour. Default limits apply where no sign is posted, and are frequently lower through towns. Approximate conversions to mph are shown for US drivers.
| Road Type | Limit (km/h) | Approx. mph |
|---|---|---|
| Urban / built-up areas | 30–40 | 19–25 |
| Motorbikes (general) | 30 | 19 |
| Rural / open roads | 90 | 56 |
| Expressway (PP–Sihanoukville) | 100–120 | 62–75 |
Cambodia now has its first expressway, linking Phnom Penh and Sihanoukville, where higher limits and stricter enforcement apply. Elsewhere, speed enforcement is inconsistent, but excessive speed near towns and schools is a common reason foreigners get stopped.
Police & How Enforcement Actually Works
Traffic is policed by the National Police traffic division (in Khmer, part of the Cambodian National Police). Enforcement style is very different from the US:
- Checkpoints and manual stops are the main tool, not automated cameras — though cameras are expanding in Phnom Penh and on the expressway.
- Officers often position themselves at junctions and wave over selected vehicles, and foreigners on scooters are a frequent target.
- Stops can end in a formal fine or an informal, negotiated cash payment — usually small.
- Presenting a valid IDP alongside your US license is the cleanest way to handle a stop, because it's the document police expect from a foreign driver.
We cover the money side of this in detail on the Cambodia driving fines page. The short version: be calm, be polite, carry proper documents, and ask for an official receipt if a fine is claimed.
Drink-Driving Limits & Penalties
Cambodia sets a legal blood-alcohol limit of 0.05% BAC for car drivers — the same threshold used across much of the world and stricter than the US 0.08% standard. Enforcement has increased in recent years, especially at night in Phnom Penh and Siem Reap.
- Roadside breath tests are used, particularly at evening checkpoints.
- Penalties escalate with BAC level and can include fines from roughly $50 to $200+, license consequences, and short detention.
- Given the chaotic road environment and the prevalence of scooters, the practical advice is simple: do not drink and drive at all in Cambodia. Tuk-tuks and Grab are cheap and everywhere.
Mixing even one drink with an unfamiliar scooter in Cambodian traffic is how many tourist accidents happen. Keep it at zero when you're driving.
Mandatory Equipment & Behavior
- Motorbike helmets: Legally required for the driver; strongly advised for passengers. Head injuries are the leading cause of tourist road deaths here, so wear one regardless of enforcement.
- Seatbelts: Required for front-seat car occupants. Rear belts are often missing in older vehicles.
- Headlights: Must be used at night; many rural roads are unlit, so working lights are essential, not optional.
- Documents: Carry your passport, US license, and IDP together whenever you drive.
- Horn: Used constantly and non-aggressively — a light tap means "I'm here," especially when overtaking. It's communication, not anger.
Phone-Use Law
Using a handheld phone while driving is prohibited and carries a fine of roughly $6–$15 (25,000–60,000 riel). You'll see locals ignore this constantly, but a foreigner texting at a light is an easy target for a stop.
If you rely on Google Maps, mount your phone and set the route before you move. Given how much your attention is needed for the surrounding motorbike swarm, hands-free navigation isn't just legal cover — it's a genuine safety necessity.
Khmer Road Signs Americans Should Recognize
Cambodia largely uses international pictogram signs, so most are intuitive. But some carry Khmer script, and knowing the key ones helps. Here are the signs and words worth recognizing:
| Sign / Word | Meaning | Notes |
|---|---|---|
| Red octagon "STOP" | Stop | Usually in English; often ignored locally, but obey it |
| Red circle, white bar | No entry | Standard international sign |
| Blue circle, white arrow | Mandatory direction | Follow the arrow |
| Red circle, number | Speed limit | Always km/h |
| Yellow diamond | Warning / caution | Curves, junctions, animals |
| Khmer text on blue signs | Place / direction names | Major routes also show Latin script and route numbers (e.g., NR6 to Siem Reap) |
National Roads are numbered (NR1, NR4, NR6, etc.) and signed in both Khmer and Latin letters on major routes, so navigation by route number is reliable.
Right-of-Way Conventions (Or the Lack of Them)
This is where US instincts fail hardest. Formal right-of-way rules exist, but on the street, priority is negotiated by size, speed, and confidence:
- Bigger vehicles effectively have priority. A bus or truck will take the space; yield to it regardless of who technically has the right.
- Roundabouts flow counter-clockwise, but entering traffic often doesn't yield. Move steadily and predictably; don't stop dead.
- Merging motorbikes filter in from every angle without stopping. Maintain a slow, constant speed so they can read you.
- Turning across traffic is done gradually — vehicles nose out and edge through gaps rather than waiting for a full opening.
- Pedestrians do not have reliable right of way; watch for people crossing anywhere.
The golden rule: move slowly, predictably, and defensively. Sudden stops and aggressive moves cause accidents because everyone around you is reading your flow, not the rulebook.
Cambodia-Specific Quirks
- USD everywhere: Fuel, fines, and rentals are priced in US dollars; riel is used as small change under $1.
- Night driving danger: Rural roads are often unlit, with livestock, ox-carts, and oncoming high beams. Avoid intercity driving after dark.
- Horn as radar: Frequent light honking is normal and courteous, signaling your presence when passing.
- Fuel from bottles: Countryside fuel is sometimes sold from glass bottles at roadside stalls; fill up in towns.
- Toll on the expressway: The Phnom Penh–Sihanoukville expressway is tolled; keep USD or a card handy.
- Flooding in wet season: May–October rains can flood roads quickly, especially in Phnom Penh; standing water hides potholes.
Frequently Asked Questions
Driving in Cambodia? Get Your IDP First
It's officially required for foreign drivers, costs about $20, and is the cleanest way to handle a Cambodian police stop. Same-day at AAA or 1–2 weeks by mail.