6.4 Hazard Perception & Accident Anticipation
Key Takeaways
Hazard perception (การรับรู้สถานการณ์อันตราย) and accident anticipation (การคาดการณ์อุบัติเหตุ) are part of the DLT's safe-driving material and practice-test categories.
Thai government road-safety figures attribute more than 80% of crashes to road-user behaviour rather than to vehicles or roads.
A driver should keep a space cushion on four sides of the car: front, rear, left, and right.
When passing parked cars, the key hazard to anticipate is a door opening suddenly or a person stepping out.
The safest response to a developing hazard is usually to slow down early and keep space, not to swerve or brake late.
6.4 Hazard Perception & Accident Anticipation
Quick Answer: Hazard perception means spotting a developing danger early enough to avoid it. The DLT's safe-driving material and practice-test categories include hazard perception (การรับรู้สถานการณ์อันตราย) and accident anticipation (การคาดการณ์อุบัติเหตุ). These questions describe a traffic scene and ask what could happen next or what you should do. The core skills are scanning well ahead and all around, predicting what other road users might do, keeping a space cushion on all four sides (front, rear, left, and right), and choosing the response that gives you time and room: usually slowing down early rather than braking or swerving late.
According to Thai government road-safety figures, more than 80% of crashes come from road-user behaviour, such as carelessness, lack of skill, or poor safety awareness, rather than from the vehicle or the road. In 2022, Thailand recorded about 14,700 road deaths. Hazard perception targets the human part of that problem.
1. See, Predict, Decide, Act
Good drivers work through the same four steps all the time:
- See: Look well down the road (roughly 10–15 seconds ahead in town and farther on highways), not just at the car in front. Check your mirrors every few seconds and before any change of speed or position.
- Predict: Ask what each road user might do. That parked car may pull out, the child may run into the road, the motorcycle may cut across.
- Decide: Choose the response that keeps the most time and space: ease off, cover the brake, move over, or wait.
- Act: Act early and smoothly. Late, harsh reactions are what turn hazards into crashes.
2. The Four-Sided Space Cushion
You manage space on four sides: front, rear, left, and right. A DLT-style question asks which of these is not a direction to keep space in, and the answer is "above".
- Front: At least a 2-second gap, more in the wet (6.1), as section 40 of the Land Traffic Act requires.
- Rear: If someone tailgates, increase the gap in front so you can brake gently, and let them pass when it is safe.
- Left and right: Avoid driving alongside other vehicles, especially in a truck's blind spot. Leave room for motorcycles and for a door opening on a parked car.
- An escape route: Always know where you could steer if the vehicle ahead stopped suddenly.
3. Classic Thai Hazard Scenes
| Scene | What Might Happen | Best Response |
|---|---|---|
| Passing a row of parked cars | A door opens suddenly, or someone steps out between cars | Slow down, leave a door's width of space, watch for feet under the cars and people inside |
| Bus stopped at a stop on the left | Passengers walk out in front of the bus; the bus pulls out | Slow right down, be ready to stop, and do not overtake it fast |
| Queue of cars stopped for a crossing | A pedestrian hidden by the queue steps into your lane | Never overtake a vehicle stopped at a crossing (section 46) |
| Car waiting to come out of a soi | It pulls out in front of you | Ease off and cover the brake. Make eye contact if you can |
| Motorcycles filtering on your left at a junction | A rider passes on your left as you turn | Check the left mirror and blind spot before turning. Signal 30 m ahead |
| Large truck turning left | It swings out to the right first, then its rear wheels cut in | Stay back and never go up its inside |
| Oncoming vehicle overtaking on a two-lane road | It cannot get back in time | Slow down and move to the left edge to give it room |
| Ball or child near the road, or a school zone | A child runs out | Slow down early and be ready to stop |
| Dogs, cattle, or buffalo on a rural road | An animal crosses unpredictably | Slow down. Brake in a straight line rather than swerving into oncoming traffic (6.3) |
| First rain after a dry spell | The road surface becomes greasy | Slow down, increase the gap, avoid harsh inputs (7.1) |
4. Clues That a Hazard Is Developing
- Brake lights several cars ahead, or a sudden gap in an oncoming queue.
- Wheels turning on a parked or waiting vehicle, before it actually moves.
- Heads turning in a car or on a motorcycle, which often comes before a lane change.
- Shadows and feet under parked vehicles and around bus stops.
- Road signs and markings: warning signs (2.3), school signs, and double solid lines all tell you where to expect trouble.
- Changes in the road surface: puddles, gravel, fallen fruit, and oil.
5. Building the Skill
- Commentary driving: As a passenger, or when practising with a teacher, say out loud what you see and what could happen. It trains your eyes to look ahead.
- Keep your attention on driving: A hand-held phone is banned (section 43(9)). Even hands-free calls and in-car screens take your attention off hazards.
- Manage fatigue: A tired driver sees hazards later. Rest about every 2 hours on long trips.
- Stay sober: Alcohol narrows attention and slows reactions well before you feel drunk (1.2).
DLT Theory Test Traps
- The "best" answer is usually the earliest safe one: slowing down, keeping space, being ready to stop. Late swerving, horn-blowing, or accelerating past a hazard is almost never correct.
- Space cushion directions: front, rear, left, and right. Not "above".
- Parked cars: The hazard the test wants you to spot is usually a door opening suddenly or a person stepping out.
You are driving past a long row of cars parked on the left. Which hazard should you anticipate most?
A car door opening suddenly, or a person stepping out between the cars
A parked car's alarm going off
The parked cars rolling backward into your path
Traffic lights changing further ahead
A defensive driver keeps a space cushion around the vehicle. Which of these is NOT one of the directions in which to keep space?
In front of the vehicle
To the left of the vehicle
To the right of the vehicle
Above the vehicle
A bus has stopped at a bus stop on your left and passengers are getting off. What is the safest action?
Slow right down and be ready to stop, because passengers may walk out in front of the bus
Speed up to pass the bus before it pulls out
Sound the horn continuously as you pass the bus
Overtake the bus on the left through the bus stop
Sections you finish are checked off in the contents.