4.2 Roundabouts & Emergency Vehicle Priority
Key Takeaways
Traffic goes around Thai roundabouts clockwise, and under section 73 entering drivers give way to vehicles already in the roundabout on their right unless signals or signs say otherwise.
Under section 76 of the Land Traffic Act, drivers must stop or park close to the left edge of the road when an emergency vehicle uses flashing lights or a siren.
Section 76 forbids stopping inside a junction to make way; clear the junction first.
At pedestrian crossings, drivers must slow down (section 70) and stop for people crossing; failing to stop carries a fine of up to 4,000 THB.
4.2 Roundabouts & Emergency Vehicle Priority
Quick Summary: In Thailand, drivers go around a roundabout keeping it on their right, so traffic moves clockwise (section 51). Unless signals or signs say otherwise, entering drivers must give way to vehicles already in the roundabout on their right (section 73). When an emergency vehicle is using flashing lights or a siren, drivers must stop or park close to the left edge of the road, but never inside a junction (section 76). At pedestrian crossings, drivers must slow down (section 70) and stop for people crossing.
Navigating multi-vehicle circulatory junctions, interacting with high-priority emergency responders, and protecting vulnerable road users at pedestrian crossings are essential skills tested on the Department of Land Transport (DLT) examination. The Land Traffic Act B.E. 2522 (1979) provides specific statutory mandates designed to prevent collisions in circular junctions and ensure life-saving emergency services can transit roadways without hindrance.
1. Roundabout Right-of-Way Rules (วงเวียน)
A roundabout is a channelized circular intersection where traffic moves continuously around a central island. Because Thailand operates on a left-hand drive network, traffic circulates around roundabouts in a clockwise direction.
The Golden Rule of Roundabouts
Under section 73 of the Land Traffic Act, unless the roundabout has its own signals or signs, entering drivers must let vehicles already in the roundabout on their right go first:
- Traffic entering the roundabout must yield to all vehicles traveling within the circulatory roadway.
- Because circulatory flow moves clockwise, vehicles inside the roundabout will approach entering drivers from their RIGHT.
- Entering drivers must decelerate, prepare to stop behind the entrance yield line, and enter only when a safe, continuous gap in circulatory traffic opens.
Lane Discipline and Signaling in Roundabouts
Navigating multi-lane roundabouts requires planning lane selection well before arrival:
- First Exit (Left Turn / 90°):
- Approach in the leftmost lane with your left turn indicator activated.
- Enter the outer circulatory lane of the roundabout.
- Maintain the left indicator and exit directly into the left lane of the departing roadway.
- Second Exit (Straight Ahead / 180°):
- Approach in the left or middle lane depending on road markings; do not indicate upon approach.
- Maintain your lane within the circulatory roadway.
- Activate your left turn indicator immediately after passing the first exit to signal your intent to leave at the second exit.
- Third Exit or Beyond (Right Turn / 270° or U-Turn):
- Approach in the rightmost lane with your right turn indicator activated.
- Enter and circulate within the innermost lane of the roundabout, keeping the right indicator on.
- As you approach your designated exit, conduct a mirror and left shoulder check, activate your left turn indicator immediately after passing the exit preceding your destination, and transition smoothly to the exit lane.
2. Emergency Vehicle Priority & Driver Duties (Section 75 & 76)
Under the Land Traffic Act, authorized emergency vehicles include police cars on official duty, fire brigade engines en route to fire scenes, municipal disaster mitigation vehicles, and certified ambulances transporting patients or responding to medical emergencies.
Mandatory Driver Actions Under Section 76
When an emergency vehicle on duty is using flashing lights, a siren, or another approved warning sound, section 76 requires drivers to let it pass first:
- Signal and Move Left: Signal and pull in close to the left edge of the road (ชิดขอบทางด้านซ้าย). If the leftmost lane is a bus lane, stop close beside the bus lane instead.
- Stop: Stop or park there. Slowing down while rolling on is not enough.
- Never Inside a Junction: Section 76 says you must not stop inside a junction. Clear the junction first.
- Wait: Stay stopped until the emergency vehicle, and any others following it, have passed.
The Act requires drivers to do this as quickly as they safely can.
What the Emergency Vehicle May Do (Section 75)
On duty, an emergency vehicle may use flashing lights and a siren, stop in no-stopping places, exceed the speed limit, pass signals and signs that say stop (after slowing), and ignore lane and direction rules. It must still take reasonable care. This is why other drivers must expect it to come from any direction.
Common Mistakes
- Stopping Inside a Junction: This blocks the very path the emergency vehicle needs, and section 76 forbids it.
- Tailgating the Emergency Vehicle: Following close behind to get through traffic is dangerous and is not allowed. Stay well back.
- Running a Red Light to Make Way: Do not drive into cross traffic. Move over within your own space and let the emergency vehicle go around.
3. Pedestrian Zebra Crossing Protections (Section 70)
Pedestrians are the most vulnerable road users. Driver duties at marked crossings (ทางม้าลาย) come from section 70 and from the crossing marking itself:
- Mandatory Deceleration (section 70): Reduce speed (ชะลอความเร็ว) whenever you approach a crossing, even if you cannot see anyone.
- Absolute Right-of-Way: If any pedestrian is crossing, stepping onto, or demonstrating clear intent to use the zebra crossing, the driver must bring their vehicle to a complete stop before the transverse stop line or yield markings.
- Overtaking Prohibition (section 46): No overtaking within 30 metres before a crossing, especially past a vehicle that has stopped for pedestrians.
- Parking Prohibition (section 57): No parking on a crossing or within 3 metres of it.
- Penalty: Failing to stop for a pedestrian on a crossing carries a fine of up to 4,000 THB (2022 amendment) and 1 demerit point.
4. Priority Comparison Matrix
| Operational Context | Right-of-Way Entity | Subordinate Entity | Mandatory Protocol / Distance Rule |
|---|---|---|---|
| Roundabout Navigation | Vehicles circulating inside from the RIGHT | Vehicles attempting to enter | Enter only when circulatory flow permits safe insertion |
| Emergency Responders | Police, Fire, Ambulance with sirens/lights | All general vehicular traffic | Stop or park close to the left edge, never inside a junction (section 76) |
| Pedestrian Zebra Crossings | Pedestrians crossing or preparing to cross | All approaching motor vehicles | Slow down on approach; stop completely before crossing line |
| Pedestrian Crossing Clearance | Moving pedestrians | Approaching traffic | No overtaking within 30 m before the crossing; no parking within 3 metres |
When approaching a circular roundabout in Thailand, which vehicles have the legal right-of-way according to traffic law?
Vehicles entering the roundabout have right-of-way over vehicles already inside
Vehicles approaching from the left outside lane have priority over all other traffic
The larger commercial vehicle entering the roundabout has priority
Vehicles already circulating inside the roundabout approaching from the right have right-of-way
Under section 76 of the Land Traffic Act, what must you do when an ambulance using its flashing lights and siren approaches from behind?
Speed up to stay ahead of it until you reach the next junction
Stop in the middle of the nearest junction so it can see you
Stop or park close to the left edge of the road, but not inside a junction, and let it pass
Follow closely behind it once it passes so you can get through the traffic
As you approach a designated pedestrian zebra crossing, you observe a pedestrian standing at the curb preparing to cross. What is your legal duty under Section 70?
Sound your horn to alert the pedestrian and maintain your current travel speed
Accelerate rapidly to clear the crossing before the pedestrian steps onto the roadway
Reduce speed and bring the vehicle to a complete stop before the crossing line to let the pedestrian cross
Flash your high beams and steer into the adjacent lane to bypass the crossing
Sections you finish are checked off in the contents.