Doha General Directorate of Traffic Truck & Bus
Timed mock exam· Full mock examsDoha General Directorate of Traffic - Qatar Truck & Bus Theory Mock Test 1
A full 40-question timed practice exam for the Qatar heavy-vehicle (truck and bus) theory test, set at the reported 37/40 (92.5%) pass mark. Covers shared road rules and signs plus heavy-vehicle handling and safety.
What does this sign mean?
The other 30 questions in this test
Read them all. The answer and the reason for each, and the timed 40-question run, are in the Qatar Driving Theory Online Practice Bank.
- Q11Penalties and fines
A driver is caught with alcohol in their system in Qatar. Which outcome is most likely for an expatriate offender?
- AA written warning for a first offence only.
- BA fine equivalent to a minor speeding ticket.
- CCriminal prosecution, imprisonment and possible deportation.
- DMandatory attendance at a road-safety workshop.
Answer and explanation in the bank
- Q12Heavy vehicle
How does brake fade affect a heavy vehicle descending a long steep hill?
- ARepeated hard braking overheats the brake drums or discs, reducing friction and extending stopping distances
- BBrake fade only affects motorcycles; heavy vehicles use air brakes that are immune
- CBrake fade increases braking power by expanding the brake shoes against the drum
- DBrake fade causes the air pressure gauge to drop below the safe operating level immediately
Answer and explanation in the bank
- Q13Road signs and signals
What does this sign tell you?
- AThe minimum speed allowed is 40 km/h
- BThe maximum speed allowed is 40 km/h
- CYou are 40 kilometres from the next city
- DRecommended speed in wet conditions is 40 km/h
Answer and explanation in the bank
- Q14Traffic rules
When approaching a roundabout in Qatar, who has priority?
- AVehicles entering from the right
- BVehicles entering from the main approach road
- CVehicles already circulating inside the roundabout
- DThe vehicle that arrived at the roundabout first
Answer and explanation in the bank
- Q15Right of way
You hear a siren and see blue and red flashing lights from an emergency vehicle approaching from behind. What must you do?
- ASpeed up to clear the road quickly
- BContinue at the same speed but stay in your lane
- CMove to the side of the road, slow down, and stop if safe to do so
- DStop immediately wherever you are
Answer and explanation in the bank
- Q16Safe driving
Why does stopping distance increase significantly on a wet road compared with a dry road?
- AWater reduces tyre friction with the road surface
- BRain makes the brakes heat up faster
- CWipers slow the vehicle down
- DWet air is heavier and adds resistance
Answer and explanation in the bank
- Q17Penalties and fines
You are stopped at a traffic checkpoint in Qatar and an officer detects the smell of alcohol on your breath. What should you expect?
- AImmediate arrest and criminal proceedings regardless of the quantity consumed.
- BA breathalyser test and, if below 0.05%, a fine only.
- CA verbal warning and confiscation of your keys for that night.
- DA licence suspension of 30 days without further action.
Answer and explanation in the bank
- Q18Heavy vehicle
What is the primary purpose of an exhaust brake (Jake brake) on a heavy vehicle?
- ATo reduce exhaust emissions by burning unburnt fuel in the exhaust system
- BTo use engine compression to slow the vehicle on descents without using the service brakes
- CTo automatically apply the parking brake when the engine is switched off
- DTo prevent the engine from over-revving when the accelerator is pressed too hard
Answer and explanation in the bank
- Q19Road signs and signals
What is the speed limit shown on this sign?
- A60 km/h maximum
- B60 km/h minimum
- C60 km/h recommended only at night
- D60 km/h advisory speed on curves
Answer and explanation in the bank
- Q20Traffic rules
You want to take the third exit at a two-lane roundabout in Qatar. Which lane should you generally use to enter?
- AThe right lane, signalling right on entry and left before your exit
- BEither lane, as lane discipline inside roundabouts is optional
- CThe right lane, and signal right continuously throughout
- DThe left lane, signalling left on approach, then signal right as you pass the exit before yours
Answer and explanation in the bank
- Q21Right of way
A pedestrian is waiting at a marked pedestrian crossing. You are approaching in a vehicle. What must you do?
- ASlow down and stop to let the pedestrian cross
- BSound your horn to signal the pedestrian to wait
- CContinue at the same speed; pedestrians must wait for vehicles
- DFlash your headlights and proceed
Answer and explanation in the bank
- Q22Safe driving
You are driving on a desert road and your front wheels begin to skid on a patch of loose sand. What should you do?
- AApply the brakes firmly to stop the skid
- BAccelerate to regain traction quickly
- CTurn the steering wheel sharply in the opposite direction
- DEase off the accelerator, steer gently, and avoid harsh braking
Answer and explanation in the bank
- Q23Penalties and fines
Which statement best describes how Qatar's alcohol driving law differs from that of many Western countries?
- AQatar allows up to 0.02% BAC, which is stricter but not zero.
- BQatar only applies its alcohol law to commercial vehicle drivers.
- CQatar sets the BAC limit at absolute zero, so any alcohol at all is an offence, whereas many Western countries permit up to 0.05% or 0.08%.
- DQatar and most Western countries share the same 0.05% BAC limit.
Answer and explanation in the bank
- Q24Heavy vehicle
Before descending a long steep grade, what gear selection technique should a heavy vehicle driver use?
- ABegin in a high gear and downshift gradually once the vehicle gains speed
- BPlace the gearbox in neutral to save fuel and allow free-rolling
- CUse the highest gear possible to keep engine revs low
- DSelect a low gear before starting the descent and maintain it throughout
Answer and explanation in the bank
- Q25Road signs and signals
What is the maximum speed permitted where this sign is displayed?
- A110 km/h
- B100 km/h
- C120 km/h
- D80 km/h
Answer and explanation in the bank
- Q26Traffic rules
A vehicle entering a roundabout in Qatar fails to give way and collides with your car. Who is normally at fault?
- AThe entering driver, as circulating traffic always has priority
- BYou, because you should have slowed to let them in
- CBoth drivers equally, as roundabouts are shared spaces
- DThe driver on the left, regardless of position
Answer and explanation in the bank
- Q27Right of way
You want to turn left across oncoming traffic. When may you complete the turn?
- AOnly when there is a safe gap in the oncoming traffic
- BAs soon as you reach the centre of the junction
- CWhen the oncoming driver slows down
- DImmediately, because turning vehicles have priority
Answer and explanation in the bank
- Q28Safe driving
What is aquaplaning (hydroplaning) and what is the correct response when it occurs?
- AThe engine overheats in rain; turn off the engine immediately
- BThe windscreen mists up; apply the rear demister
- CThe wipers cannot clear the screen; increase wiper speed
- DThe tyres ride on a film of water; ease off the accelerator and steer straight until grip returns
Answer and explanation in the bank
- Q29Penalties and fines
Which action is illegal while driving in Qatar under the mobile phone regulations?
- AUsing a phone mounted on the dashboard in a holder.
- BReceiving a call through a built-in Bluetooth hands-free system.
- CPlaying music through the car speakers via Bluetooth.
- DHolding and using a mobile phone in your hand while the vehicle is moving.
Answer and explanation in the bank
- Q30Heavy vehicle
What happens to braking performance if air pressure in a pneumatic brake system drops below the minimum safe level?
- AThe service brakes switch to a hydraulic backup circuit
- BSpring-loaded park brakes automatically apply, immobilising the vehicle
- CThe brakes lock permanently until the air tank is refilled at a service station
- DThe ABS system takes over to compensate for the reduced air pressure
Answer and explanation in the bank
- Q31Road signs and signals
What does this sign prohibit?
- ADriving in the right lane
- BTwo vehicles travelling abreast
- CParking two cars side by side
- DOvertaking other vehicles
Answer and explanation in the bank
- Q32Traffic rules
On which side of the road are you permitted to overtake another vehicle in Qatar?
- AOn the left; you may pass on the right only when the vehicle ahead has signalled and is turning left
- BOn the right side only, because Qatar uses left-hand traffic
- COn either side, whenever there is space
- DOn the hard shoulder if the left lane is busy
Answer and explanation in the bank
- Q33Right of way
You are driving in a filter lane that is merging with the main lane. How should the merge be handled?
- AVehicles in the main lane must always slow and allow the filter vehicle in
- BVehicles in the filter lane must give way to traffic already in the main lane
- CThe vehicle that is travelling faster has priority
- DThe longer vehicle has priority
Answer and explanation in the bank
- Q34Safe driving
What effect does under-inflated tyre pressure have on your vehicle in Qatar's hot climate?
- AIt improves grip by increasing the tyre contact patch in all conditions
- BIt reduces fuel consumption because the tyres roll more easily
- CIt increases heat build-up in the tyre, raising the risk of a blowout
- DIt has no significant effect at speeds below 80 km/h
Answer and explanation in the bank
- Q35Penalties and fines
What penalty does a driver risk for using a handheld mobile phone while driving in Qatar?
- AOnly a verbal warning for a first offence, with no financial penalty.
- BA QR 500 fine, with no black points and no discount for early payment
- CImmediate permanent cancellation of the driving licence.
- DNo penalty if you are stopped at a red light rather than moving.
Answer and explanation in the bank
- Q36Heavy vehicle
What is the correct way to test air brakes at the start of a shift?
- ABuild air pressure to operating level, then apply the foot brake and check that pressure drops slowly within acceptable limits
- BDrive at 30 km/h and perform a full emergency stop to confirm brake response
- CApply and release the brakes five times rapidly to warm the brake linings
- DOpen the drain valves to release any moisture and then drive normally
Answer and explanation in the bank
- Q37Road signs and signals
What does this sign indicate?
- AThree-way junction ahead
- BYou may drive in any direction
- CA roundabout is ahead and you must follow the direction of the arrows
- DTraffic merging from the right only
Answer and explanation in the bank
- Q38Traffic rules
In which of the following locations is overtaking strictly prohibited in Qatar?
- AOn a straight road with good visibility
- BOn a pedestrian crossing or within the approach area to one
- COn a dual carriageway with a solid centre barrier
- DOn a road with a 60 km/h speed limit
Answer and explanation in the bank
- Q39Right of way
On a motorway, two lanes reduce to one due to a lane closure ahead. What is the correct way to merge?
- ABoth lanes travel to the merge point, then alternate one vehicle at a time (zip merge)
- BAll drivers must move to the open lane as soon as they see the signs
- CThe vehicle in the closing lane must stop and wait
- DThe faster-moving lane always has priority
Answer and explanation in the bank
- Q40Safe driving
Your front right tyre blows out at highway speed. What is the correct immediate action?
- ABrake hard immediately to stop as quickly as possible
- BTurn the steering sharply in the direction opposite to the blow-out
- CGrip the steering firmly, ease off the accelerator, and steer straight to a safe stop
- DIncrease speed briefly to regain stability then brake
Answer and explanation in the bank
Every answer above, with the rule it comes from, plus the full 40-question timed test.
Get the Qatar Driving Theory Online Practice Bank - QAR 39What this test covers
Topics include road signs, traffic signals, right of way, roundabouts, speed limits, seat belts, fines and penalties, and the safe-driving rules specific to your vehicle category. Full question-by-question feedback with explanations is shown immediately after you finish the test above.
Frequently asked questions
How many questions is the Doha General Directorate of Traffic truck & bus theory test?
The official General Directorate of Traffic truck & bus theory test in Doha has 40 questions and you need 37 correct (92.5%) to pass. This practice test has 40 questions.
Is this the real exam?
These are practice questions to help you revise, written to the published rules and to what candidates report from the real test. They are not the official Qatar exam and the real question bank, format, fees and pass mark are set by the General Directorate of Traffic (Ministry of Interior) and the driving schools, and can change. Always confirm the current requirements with your driving school or the traffic department (for example via the Metrash service).
Is this practice test free?
The first 10 questions are free, with no signup, and each shows the answer and the reason. The full 40-question test, timed, is in the Qatar Driving Theory Online Practice Bank (QAR 39, one payment), with every question in the bank.
What does the Doha truck & bus theory test cover?
Road signs, traffic signals, right of way, roundabouts, speed limits, seat belts, penalties and safe-driving rules, plus the handling and safety topics specific to your vehicle.