Traffic Law questions

English question-and-answer pages for this Thai driving license theory category.

Q29 How must a driver proceed through an intersection?
Answer: Strictly obey traffic lights or traffic rules.
Q30 Where is horn use prohibited?
Answer: Hospitals and schools.
Q31 What must a driver do before turning?
Answer: Slow down and signal at least 30 meters before the turn.
Q32 When stopping at an intersection, where must the driver stop?
Answer: Stop behind the stop line.
Q33 Where is overtaking prohibited?
Answer: On a sharp curve.
Q34 When parking, how far from the curb may the vehicle be?
Answer: No more than 25 centimeters from the curb.
Q35 A driver normally overtakes on the right. In what case may overtaking on the left be allowed?
Answer: When the vehicle being overtaken is turning right or signaling a right turn.
Q36 Where is making a U-turn prohibited?
Answer: In safety zones, congested or dangerous areas, on bridges, within 100 meters of a bridge approach, and at intersections.
Q37 What does "safety zone" mean?
Answer: An area of the roadway clearly marked at all times for pedestrians or passengers to wait before crossing.
Q38 What does a red diagonal cross traffic signal above a lane prohibit?
Answer: Driving in that lane is prohibited.
Q39 When a traffic officer extends the left arm horizontally, drivers coming from which side must stop?
Answer: From behind the officer.
Q40 When a traffic officer raises the right forearm upright with the palm up, drivers coming from which side must stop?
Answer: From in front of the officer.
Q41 How must a driver proceed through an intersection with a flashing red traffic light?
Answer: Stop first, then proceed only when it is safe and lawful.
Q42 How must a driver proceed through an intersection with a flashing yellow traffic light?
Answer: Reduce speed and pass through with caution.
Q43 Drivers must keep left. In what case may they drive on the right or cross the center line?
Answer: When there is an obstruction on the left side of the roadway.
Q44 If a driver extends the right arm straight out at shoulder height and waves the hand up and down, what does it mean?
Answer: The driver intends to reduce speed.
Q45 How much distance must a driver keep from the vehicle ahead?
Answer: A distance that allows the vehicle to stop safely when necessary.
Q46 Before turning left, how many meters before the turn must a driver move into the left lane?
Answer: At least 30 meters.
Q47 At minimum, how far must headlights or tail lights be visible to other vehicles?
Answer: 150 meters.
Q48 When driving toward oncoming traffic, what must a driver do?
Answer: Keep to the left.
Q49 Overtaking is prohibited in fog, dust, rain, or smoke when visibility ahead is less than what distance?
Answer: 60 meters.
Q50 When a driver sees a "left turn on red" sign, what should they do?
Answer: Stop and wait for pedestrians and vehicles from the right to pass before turning left.
Q51 Who does not have a duty to give traffic signals under the Road Traffic Act?
Answer: Pedestrians.
Q52 What must be done every time before changing lanes or overtaking?
Answer: Use a light signal or horn signal.
Q53 When reaching a railway crossing while a train is passing, what must a driver do?
Answer: Stop at least 5 meters from the railway track.
Q54 What is the effect if a driver flees after an accident?
Answer: The driver is presumed to be at fault.
Q55 When may a horn be used?
Answer: Only when necessary to prevent an accident.
Q56 How much following distance must be kept while driving?
Answer: A safe distance.
Q57 For a driver who has consumed alcohol, what is the maximum breath alcohol level?
Answer: No more than 50 milligrams percent.
Q58 What is the penalty if alcohol in the body exceeds the legal limit while driving?
Answer: Imprisonment up to 1 year, a fine from 5,000 to 20,000 baht, or both.
Q59 What speed limit applies in Bangkok, Pattaya City, or municipal areas?
Answer: No more than 80 kilometers per hour.
Q60 What speed limit applies outside Bangkok, Pattaya City, or municipal areas?
Answer: No more than 90 kilometers per hour.
Q61 How far away must other drivers be able to see a turn signal?
Answer: At least 60 meters.
Q62 How many meters before turning must a driver enter the proper lane and signal?
Answer: 30 meters.
Q63 At an intersection with a no U-turn sign, if a traffic officer allows a U-turn, what must the driver do?
Answer: The driver may make the U-turn.
Q64 What must a driver do before making a U-turn?
Answer: Check that traffic signs allow a U-turn and enter the correct lane.