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China truck Subject 4 safe-driving foundations study materials
China truck Subject 4 safe-driving foundations study resources

China truck Subject 4 safe-driving foundations practice questions

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Question 1Truck Technology

According to GB 1589-2016 regulations on axle loads and vehicle dimensions, what is the primary risk of loading cargo too far toward the rear of a heavy truck cargo bed?

  1. It reduces downforce on the front steering axle, leading to degraded steering control and headlight upward mispointing Correct answer.
  2. It causes immediate pneumatic failure of the service brake dual-circuit diaphragm
  3. It locks the transmission inter-axle differential into permanent 4-wheel engagement
  4. It increases front tire temperature and accelerates front tread wear

Explanation

Under GB 1589-2016 and safe loading guidelines, loading cargo excessively toward the rear shifts the center of gravity behind the rear axle fulcrum, levering weight off the front steering axle. This severely reduces front tire traction, causing dangerous understeer or complete loss of directional steering control at highway speeds, while elevating the vehicle front and blinding oncoming drivers with misaligned headlights.

Question 2Truck Technology

When backing a semi-trailer combination vehicle (重型半挂车) into a narrow loading dock, how must the driver initially manipulate the steering wheel to guide the rear of the trailer to the left?

  1. Turn the steering wheel to the right initially, then counter-steer to the left once the trailer begins pivoting Correct answer.
  2. Turn the steering wheel immediately to the hard left and hold it stationary throughout the maneuver
  3. Engage the differential lock and accelerate briskly in reverse without steering inputs
  4. Pump the service brake pedal continuously while keeping the steering wheel centered

Explanation

In articulated commercial vehicle dynamics (GA 1026-2017 Subject 2 and Subject 4 syllabi), backing requires reversed steering geometry. To push the trailer rear to the left, the tractor front must steer to the right so that the tractor rear swings right, articulating the fifth wheel kingpin. Once the trailer is angled toward the dock, the driver counter-steers left to 'follow' and catch the trailer to prevent jackknifing.

Question 3Truck Technology

When operating a high-cube van truck or double-deck commercial vehicle transporter with a high center of gravity (高重心), what is the safest driving strategy when entering an expressway interchange ramp?

  1. Reduce speed well before the ramp entrance curve, maintain a smooth steady arc, and avoid abrupt steering or braking Correct answer.
  2. Maintain highway cruising speed until reaching the curve apex, then apply emergency braking
  3. Coast through the curve in neutral to allow the high center of gravity to self-stabilize
  4. Accelerate sharply through the curve to generate downward aerodynamic downforce

Explanation

High center of gravity vehicles have a narrow lateral stability margin. Centrifugal force increases with the square of vehicle speed (F = m * v^2 / r). Under GA 1026-2017 safe driving guidelines, drivers must decelerate in the straight deceleration lane before curve entry, maintain gentle steering inputs, and avoid sudden mid-corner weight transfers that can trigger rollover.

Question 4Truck Technology

What is 'tail swing' (尾摆 / 后悬外摆) in heavy commercial vehicles, and when does it pose the greatest danger?

  1. The outward sweep of the vehicle's rear overhang on the opposite side of a turn when pulling away from curbs, walls, or parked vehicles Correct answer.
  2. The lateral vibration of the drive axle caused by an unbalanced driveshaft at highway speeds
  3. The vertical oscillation of the rear air suspension when dumping cargo from a tipper truck
  4. The aerodynamic buffeting of the rear mudflaps in heavy crosswinds

Explanation

Tail swing occurs because the portion of the truck body extending behind the rear axle (the rear overhang / 后悬) pivots outward in the opposite direction of the front steering angle. When a driver steers sharply away from a curb, loading bay, or adjacent vehicle, the rear tail can swing out 0.5 to 1.0+ meters, striking nearby objects or pedestrians if the driver fails to check mirrors before turning.

Question 5Truck Technology

When coupling a prime mover (tractor unit) to a semi-trailer, what is the purpose of conducting a 'tug test' (拉紧测试 / 牵引测试)?

  1. To physically verify that the fifth wheel locking jaws have fully engaged and locked around the trailer kingpin before raising the landing gear Correct answer.
  2. To test whether the engine turbocharger wastegate produces sufficient boost pressure
  3. To calibrate the electronic tire pressure monitoring sensors on the trailer axles
  4. To purge residual moisture and engine oil vapors from the pneumatic air dryer

Explanation

In commercial combination vehicle coupling procedures, a tug test involves gently attempting to pull the tractor forward in low gear while the trailer brakes remain locked. This mechanically verifies that the fifth wheel locking jaws (鞍座锁止机构) have firmly closed around the trailer kingpin (牵引销). If the jaws did not latch, the trailer would drop onto its landing gear rather than detaching at highway speed.

Question 6Truck Technology

Which specialized indirect vision mirror on heavy trucks is specifically designed to eliminate the blind spot directly in front of the high cab bumper (Class VI front-view mirror / 前下视镜)?

  1. The front downward cross-view mirror mounted above the windshield to view pedestrians and obstacles immediately adjacent to the front bumper Correct answer.
  2. The interior rearview mirror mounted on the center cab dome
  3. The standard flat main mirror (Class II) mounted on the driver's side door
  4. The aerodynamic rear fender camera used for highway cruising alignment

Explanation

Under GB 15084 and GB 7258-2017, large trucks with elevated cab-over-engine designs must be fitted with a Class VI front-view mirror (前下视镜) mounted above the windshield. This mirror allows the seated driver to view the blind area extending from the front bumper out to several meters, preventing tragic front-blind-spot collisions with pedestrians or children when starting from a dead stop.

Question 7Truck Technology

When should a heavy truck driver engage the inter-axle differential lock (轴间差速锁), and what critical precaution must be observed after returning to normal paved roads?

  1. Engage only when one drive axle loses traction on mud/ice while traveling in a straight line; disengage immediately before turning or driving on hard paved roads Correct answer.
  2. Engage permanently during all highway driving to equalize tire wear across tandem axles
  3. Engage when descending steep mountain grades to assist the exhaust brake at high speeds
  4. Engage only when backing into a loading dock on dry concrete at full steering lock

Explanation

The inter-axle differential lock rigidly couples the tandem drive axles, forcing both to rotate at identical speed. It is strictly used in low-traction off-road conditions (mud, snow, sand) in a straight line. If left engaged on dry paved roads or during turns, it causes severe drivetrain wind-up (传动系扭滞), tire scrubbing, inability to steer, and potential axle shaft or differential gear destruction.

Question 8Truck Technology

When transporting heavy cylindrical cargo (such as hot-rolled steel coils / 钢卷) on a flatbed semi-trailer, what specialized securing method is essential to prevent the cargo from rolling forward through the driver's cab during sudden braking?

  1. Placing coils in contoured steel cradles with hardwood wedge chocks (三角木垫) and applying direct heavy-duty chain tie-downs with load binders Correct answer.
  2. Stacking coils vertically on top of each other without cradles to maximize bed friction
  3. Relying on standard synthetic straps without wood chocks or steel cradles
  4. Placing coils loose against the front cab bulkhead so they cannot move further forward

Explanation

Steel coils represent extreme concentrated loads with high momentum and low rolling resistance. Under Ministry of Transport cargo restraint standards, steel coils must be seated in dedicated structural steel cradles/saddles (专用鞍座), blocked with heavy hardwood wedge chocks (三角木) to prevent rolling, and restrained with high-tensile alloy steel chains and ratchet binders. Placing loose coils against the headboard is fatal, as a shifting multi-ton coil will easily crush the cab during emergency braking.

Question 9Truck Technology

When descending a long, steep mountain grade in a heavy commercial truck, how should auxiliary braking devices (such as the engine exhaust brake / 排气制动 or hydraulic retarder / 液力缓速器) be utilized?

  1. Engage the auxiliary brake in conjunction with a matching low transmission gear to maintain a steady safe speed, minimizing service brake use Correct answer.
  2. Shift the transmission into neutral and rely solely on the auxiliary exhaust brake
  3. Use the service foot brake continuously while leaving the auxiliary brake turned off
  4. Engage the auxiliary brake only after the service brakes begin smoking and fading

Explanation

According to GA 1026-2017 and heavy vehicle safe operation guidelines, on long continuous downhill sections, drivers must select a low gear and engage auxiliary braking systems (exhaust brake, compression release brake, or hydraulic retarder). This converts vehicle kinetic energy into engine pumping work or fluid friction, controlling descent speed without overheating the wheel service brake drums/discs.

Question 10Truck Technology

How does a hydraulic retarder (液力缓速器) generate retarding torque on heavy commercial trucks without causing mechanical wear?

  1. It circulates hydraulic oil between a rotating rotor and a stationary stator, using fluid shearing resistance to absorb driveline kinetic energy and transferring the heat to the engine coolant Correct answer.
  2. It clamps carbon ceramic friction discs directly to the driveshaft using high-pressure hydraulic fluid
  3. It injects high-pressure hydraulic fluid into the engine combustion chambers to stop the pistons
  4. It reverses the polarity of the alternator to create an electromagnetic magnetic field in the rear differential

Explanation

Under GB 7258-2017 auxiliary braking specifications, a hydraulic retarder operates on hydrodynamic principles: hydraulic transmission oil is pumped between a rotating rotor (connected to the transmission output/driveshaft) and a stationary housing stator. The resulting fluid turbulence and shearing resistance decelerate the driveshaft smoothly without contact wear, with generated heat dissipated through the vehicle's engine cooling radiator.

Question 11Truck Technology

Why is it dangerous to operate a hydraulic retarder or engine compression brake at maximum stage on wet, icy, or snow-covered mountain roads?

  1. High retarding torque applied exclusively to the drive axle can cause the drive wheels to break traction and lock/slide, triggering a tractor-trailer jackknife Correct answer.
  2. The retarder will overheat the engine cooling fluid within seconds in sub-zero weather
  3. The hydraulic oil will instantly freeze in the retarder valve block and burst the radiator
  4. The auxiliary brake will deactivate the pneumatic trailer supply line and dump trailer air

Explanation

On slippery road surfaces (ice, snow, mud), the tire-to-road friction coefficient is very low. Because retarders and engine brakes deliver substantial retarding torque strictly to the tractor's drive axle(s), high-stage retarder activation can exceed available tire grip, locking the drive wheels. When drive wheels lose lateral adhesion, the semi-trailer pushes forward against the articulated joint, causing instantaneous jackknifing.

Question 12Truck Technology

What is the purpose of an emergency escape ramp (避险车道 / 减速车道) situated along long, steep highway descents, and what are its main structural components?

  1. To safely arrest runaway heavy vehicles suffering brake failure using an upward slope, deep gravel arrester bed (制动床), and energy-absorbing safety barriers Correct answer.
  2. To provide an express overtaking lane for high-speed passenger cars passing slow trucks
  3. To serve as a scenic rest viewpoint for drivers to cool tires and check cargo straps
  4. To function as a dedicated staging lane for heavy vehicle weight enforcement scales

Explanation

Emergency escape ramps (避险车道) are specialized safety facilities engineered into long downhill highway corridors. They consist of an entry guide path, an upward-sloping deceleration bed filled with deep uncompacted gravel/sand (制动床), anchor blocks for winch recovery, and energy-absorbing barrel/tire barriers at the terminus to bring out-of-control vehicles with failed brakes to a safe, controlled stop.

Question 13Truck Technology

When a heavy truck driver experiences total service brake failure on a mountain descent and identifies an emergency escape ramp (避险车道) ahead, how should the vehicle be steered into the ramp?

  1. Align the vehicle smoothly into the center of the ramp entrance, grip the steering wheel firmly with both hands, and steer straight into the gravel bed without making sharp turns Correct answer.
  2. Swerve violently back and forth across the gravel bed to maximize friction against the side curbs
  3. Apply the trailer hand brake hard and steer sideways to intentionally flip the truck on the entry ramp
  4. Attempt to turn around 180 degrees at the ramp entrance to roll back uphill

Explanation

When entering an escape ramp, the driver must guide the vehicle straight into the centerline of the arrester bed. Deep gravel will rapidly sink the wheels and exert massive drag forces. The driver must grip the steering wheel firmly with both hands to resist aggressive front-wheel pulling and maintain a straight trajectory, preventing the vehicle from flipping or jumping the side retaining barriers.

Question 14Truck Technology

What is the primary physical cause of tractor-trailer jackknifing (半挂车折叠 / 折头 / 甩尾) during high-speed driving or braking on slippery roads?

  1. The drive wheels of the tractor lose traction and slide laterally while the semi-trailer pushes forward against the fifth wheel articulation pivot Correct answer.
  2. The fifth wheel kingpin dissolves due to static electricity accumulation
  3. The front steer tires freeze and lock at a 90-degree angle to the tractor frame
  4. The trailer air springs over-inflate and lift the trailer wheels into the air

Explanation

Jackknifing is an instability of articulated vehicles where the tractor and semi-trailer rotate relative to each other about the fifth wheel kingpin. When the tractor drive wheels lock or lose lateral adhesion (e.g., during harsh braking or over-retarding on wet/icy roads), the momentum of the heavier trailing trailer pushes the tractor rear sideways, folding the combination like a pocket knife.

Question 15Truck Technology

If the hydraulic power steering assist (动力转向系统) suddenly fails while driving a heavy loaded truck at speed, what will the driver experience and how should they respond?

  1. The steering wheel becomes extremely heavy and difficult to turn; the driver must grip the wheel with maximum physical force with both hands, reduce speed steadily, and steer onto the shoulder Correct answer.
  2. The steering wheel spins freely with zero resistance and disconnects from the front wheels
  3. The vehicle immediately accelerates out of control due to power steering pump backpressure
  4. The driver should release the steering wheel completely and use the trailer hand brake to steer

Explanation

Commercial heavy trucks utilize hydraulic power steering with direct mechanical recirculating ball/rack linkages. If the power steering belt snaps or hydraulic fluid is lost, the mechanical linkage remains intact, but manual steering effort increases drastically. The driver must exert full upper-body strength with both hands to maintain lane position, ease off the accelerator, and steer steadily to the emergency lane.

Question 16Truck Technology

If the accelerator pedal becomes stuck wide open (油门踏板卡死) while driving a heavy manual transmission truck, what is the immediate first action?

  1. Immediately depress the clutch pedal fully (or shift into neutral) to disconnect engine power from the wheels, apply service brakes firmly, steer to safety, and turn off the ignition Correct answer.
  2. Pump the accelerator pedal repeatedly while steering into oncoming traffic
  3. Pull the parking brake with maximum force while leaving the clutch fully engaged in high gear
  4. Unbuckle seatbelt and climb down into the footwell to unstick the pedal with hands while driving

Explanation

When an accelerator sticks wide open, the priority is to cut motive power to the drive wheels immediately. Depressing the clutch pedal (or shifting to neutral) separates engine torque from the transmission in a fraction of a second. The driver can then safely apply the service brakes to bring the truck to a controlled stop on the shoulder and switch off the engine.

Question 17Truck Technology

What safety feature automatically activates on an articulated semi-trailer if it accidentally detaches from the tractor unit while driving (挂车脱钩事故)?

  1. The severed pneumatic supply line dumps air pressure, causing the trailer emergency relay valve (挂车继动阀) to apply full spring emergency braking, stopping the detached trailer Correct answer.
  2. The trailer wheels automatically steer toward the right-hand ditch at 45 degrees
  3. The trailer activates auxiliary electric motors to drive itself to the nearest service area
  4. The trailer parachute deploys from the rear doors to slow aerodynamic momentum

Explanation

Under GB 7258-2017 dual-line pneumatic brake standards, if a semi-trailer uncouples, the red supply air hose severs. This sudden loss of supply pressure causes the trailer emergency relay valve (紧急继动阀) to instantly vent the trailer spring brake chambers, locking all trailer brakes at maximum force to bring the detached trailer to a rapid automatic emergency halt.

Question 18Truck Technology

When the rear wheels of a rigid cargo truck lose traction and experience a lateral skid (后轮侧滑 / 甩尾) on a wet road, how should the steering wheel be manipulated?

  1. Ease off the accelerator and steer gently in the SAME direction as the rear-end skid (同向打方向盘), straightening as soon as traction returns Correct answer.
  2. Slam on the service brakes and turn the steering wheel hard in the OPPOSITE direction of the skid
  3. Accelerate to full throttle and lock the steering wheel completely to the left
  4. Pull the spring emergency brake and hold the steering wheel centered

Explanation

For rear-wheel skids (oversteer), the rear of the vehicle slides out. The driver must release the accelerator (without braking) and counter-steer gently in the direction the rear tail is sliding (e.g., if the tail slides right, steer right). As soon as the vehicle begins aligning, the driver must straighten the wheel immediately to prevent a secondary snap-back skid in the opposite direction.

Question 19Truck Technology

When a heavy truck suffers front-wheel understeer skid (前轮侧滑 / 转向不足) and fails to follow the curved path on an icy road, what is the proper correction?

  1. Ease off the throttle smoothly, do NOT increase the steering angle further, and wait for the front tires to regain rolling grip before gently guiding the vehicle Correct answer.
  2. Turn the steering wheel with maximum force into the turn and pump the service brakes rapidly
  3. Accelerate aggressively to force the front wheels to bite into the ice
  4. Apply the hand trailer brake to lock the rear axle and force a 180-degree spin

Explanation

Front-wheel understeer occurs when front steering tires exceed their available adhesion limit and slide forward tangentially. Turning the steering wheel sharper only worsens tire scrubbing and prolongs sliding. The driver must ease off the accelerator, slightly reduce steering lock to restore rolling contact, and allow tire lateral friction to recover before gently following the curve.

Question 20Truck Technology

What severe handling hazard occurs if a driver accidentally leaves the cross-axle differential lock (轮间差速锁) engaged when entering a paved high-speed curve?

  1. Both left and right wheels are forced to rotate at identical speed, generating severe understeer where the vehicle refuses to turn and plows straight ahead off the road Correct answer.
  2. The vehicle automatically turns in tight 360-degree circles on the highway
  3. The steering wheel spins freely with zero mechanical resistance
  4. The engine automatically shifts into neutral and turns off headlights

Explanation

In a curve, the outside wheel must travel a longer arc and rotate faster than the inside wheel. A locked cross-axle differential forces both wheels to rotate at identical RPM. On paved surfaces with high traction, this creates immense torque fighting the turn, causing massive front tire scrubbing and severe understeer-the truck will push straight ahead despite the driver turning the steering wheel.

Question 21Truck Technology

How should a heavy truck driver respond when the on-board Lane Departure Warning System (车道偏离预警系统 LDWS) sounds an acoustic alarm while cruising on a long highway trip?

  1. Recognize that the vehicle is drifting out of its lane without turn signals (often due to fatigue/distraction), grip the steering wheel, check mirrors, center the vehicle, and plan an immediate rest stop Correct answer.
  2. Mute the alarm, increase speed by 20 km/h, and continue driving for another 4 hours
  3. Slam on the service brakes immediately in the middle lane
  4. Assume the system is defective and unplug the camera harness while driving

Explanation

LDWS is an active safety assistance system mandated under JT/T 883 and GB 7258 for commercial vehicles. When it triggers without turn signal activation, it indicates unintended lane departure-a classic indicator of driver drowsiness, micro-sleep, or distraction. The driver must correct vehicle trajectory immediately and pull into the next service area for a mandatory rest.

Question 22Truck Technology

When a driver notices dense smoke billowing from the closed rear doors of an enclosed dry freight van trailer (厢式货车), what is the proper emergency protocol?

  1. Pull over in an open area away from structures/traffic, shut down the engine, prepare fire extinguishers, call 119, and do NOT swing the rear doors wide open immediately (to avoid oxygen flashover) Correct answer.
  2. Open the rear doors wide immediately to inspect the cargo while standing inside the van
  3. Drive as fast as possible to the nearest downtown fuel station to use their water hose
  4. Disconnect the trailer and leave it burning in the middle travel lane of the expressway

Explanation

A smoldering fire inside an enclosed cargo box consumes available oxygen. Opening the cargo doors wide causes a sudden inrush of air, resulting in explosive backdraft (爆燃) that engulfs the driver in a fireball. The driver must stop in a safe open area, maintain a sealed enclosure while preparing fire extinguishers, notify the fire rescue service (119), and crack the door only with charged extinguishers ready.

Question 23Truck Technology

Under national standard GB 190 (Hazardous Goods Packaging Signs), which of the following hazard classes is represented by an orange diamond placard displaying an exploding bomb symbol?

  1. Class 1: Explosives (爆炸品) Correct answer.
  2. Class 3: Flammable Liquids (易燃液体)
  3. Class 8: Corrosive Substances (腐蚀品)
  4. Class 7: Radioactive Materials (放射性物品)

Explanation

GB 190 and international UN dangerous goods codes define Class 1 as Explosives (爆炸品), marked by an orange background with an exploding bomb pictogram. Class 3 features a red diamond with a flame symbol (Flammable Liquids), Class 8 features a black-and-white diamond showing spilled liquid corroding metal and hands (Corrosives), and Class 7 features a trefoil propeller symbol (Radioactive).

Question 24Truck Technology

When an accident occurs involving a hazardous chemical road tanker with leaking toxic or flammable gas/liquid, what is the mandatory initial response for the driver and escort (押运员)?

  1. Immediately trip the emergency shut-off valve if safe, extinguish all ignition sources, evacuate all personnel UPWIND (上风向), isolate the area, and call 119/122 stating the UN number and cargo name Correct answer.
  2. Stand directly downwind in the vapor cloud to plug the leak with clothing
  3. Use an open flame lighter to check if the leaking gas is flammable
  4. Instruct passing motorists to drive faster through the chemical cloud to disperse it

Explanation

Under the PRC Regulations on the Safety Administration of Hazardous Chemicals, drivers and escorts must immediately attempt to trip the external emergency shut-off valve if accessible without personal danger, prohibit smoking and open flames, evacuate immediately in an UPWIND (上风向) direction, establish an isolation perimeter, and dial 119/110/122 providing the UN number, shipping name, and leak volume.

Question 25Truck Technology

What is the specific industrial and transport safety risk associated with bulk transportation of finely ground agricultural powders (such as grain flour, starch, or pulverized coal / 粮食、淀粉、煤粉散装运输)?

  1. Combustible dust explosion risk (粉尘爆炸): suspended fine particles in enclosed hoppers can violently ignite and explode from static sparks or open flames Correct answer.
  2. Fine powder dissolves the vehicle's steel chassis on contact
  3. Bulk flour generates gamma radiation when exposed to air
  4. Grain dust freezes into solid ice at high summer temperatures

Explanation

Combustible agricultural dusts (flour, grain dust, starch, wood flour, coal dust) have massive surface-area-to-mass ratios. When suspended in air inside an enclosed tanker or loading hopper at explosive concentration limits, a tiny electrostatic discharge, friction spark, or hot surface will trigger a devastating supersonic dust explosion (粉尘爆炸). Loading and transport require anti-static grounding and spark-free equipment.

Question 26Truck Technology

Under Ministry of Transport regulations on hazardous freight transport (道路危险货物运输管理规定), what documents must commercial drivers and escorts carry on board during every hazardous cargo shipment?

  1. Dangerous goods transport manifest (道路危险货物运单), Material Safety Data Sheet (MSDS / 安全技术说明书), and emergency response instructions (应急处置卡) Correct answer.
  2. Only the driver's personal commercial receipt for fuel purchases
  3. A tourist map and personal identity card without freight documentation
  4. A verbal authorization agreement without written manifests

Explanation

MOT regulations mandate that any vehicle transporting hazardous chemicals or dangerous goods must carry the official electronic/paper Dangerous Goods Waybill (运单), the chemical manufacturer's Material Safety Data Sheet (MSDS / 化学品安全技术说明书), and cargo-specific Emergency Response Cards (应急处置卡). These specify the UN number, physical properties, fire suppression agents, and first aid measures required during an accident.

Question 27Hazards Fitness

Under Ministry of Public Security Order No. 162 and the PRC Road Traffic Safety Law, what are the maximum continuous driving hours and minimum mandatory rest duration for heavy commercial vehicle drivers?

  1. Maximum 4 hours of continuous driving, followed by a mandatory rest stop of at least 20 minutes Correct answer.
  2. Maximum 6 hours of continuous driving, followed by a mandatory rest stop of at least 10 minutes
  3. Maximum 8 hours of continuous driving, followed by a mandatory rest stop of at least 15 minutes
  4. Maximum 5 hours of continuous driving, followed by a mandatory rest stop of at least 30 minutes

Explanation

Article 62 of the Road Traffic Safety Law Implementation Regulations and MPS Order 162 explicitly stipulate that drivers of medium and heavy passenger and freight vehicles must not drive continuously for more than 4 hours without stopping for rest, and each rest period must be no less than 20 minutes. Violations on expressways result in severe penalty point deductions under MPS Order 163.

Question 28Hazards Fitness

When driving an empty or high-sided van truck across a high mountain bridge or viaduct exposed to severe crosswinds (横风), what immediate action must the driver take upon feeling the steering pull sideways?

  1. Grip the steering wheel firmly with both hands, reduce speed moderately, and make gentle, progressive counter-steering corrections into the wind without overreacting Correct answer.
  2. Slam the service brakes immediately and jerk the steering wheel hard in the opposite direction
  3. Accelerate to maximum speed to cut through the crosswind airflow faster
  4. Shift the transmission into neutral and allow the wind to steer the vehicle

Explanation

High-sided commercial vehicles have large lateral surface areas acting like sails. When encountering crosswinds on bridges (marked by warning sign '横风'), the driver must hold the steering wheel firmly with both hands, ease off the accelerator to reduce speed, and make smooth, measured corrections toward the wind. Over-correcting or slamming brakes can induce severe vehicle oscillation, trailer whip, or rollover.

Question 29Hazards Fitness

According to Article 81 of the PRC Road Traffic Safety Law Implementation Regulations, what are the speed and following distance rules when visibility on an expressway is less than 50 meters due to dense fog?

  1. Turn on fog lights, low beams, clearance lamps, and hazard lights; limit speed to <= 20 km/h, and exit the expressway at the nearest ramp immediately Correct answer.
  2. Maintain 60 km/h in the fast lane and follow the taillights of the leading truck at 10 meters distance
  3. Stop immediately in the middle travel lane, turn off all lights, and wait for the fog to dissipate
  4. Activate high beam headlights and drive at 50 km/h on the emergency shoulder

Explanation

Article 81 of the Implementation Regulations establishes the standard visibility rule: when visibility is less than 50 meters, the driver must turn on fog lights, low beams, clearance lamps, and hazard flashers, must not exceed 20 km/h, and must leave the expressway at the nearest exit ramp at the earliest opportunity.

Question 30Hazards Fitness

When driving a loaded heavy truck on an expressway during torrential rain, what is 'hydroplaning' (水滑现象) and what is the proper driver response if it occurs?

  1. Tire treads fail to evacuate water, causing the tires to ride on a film of water and lose all steering/braking traction; ease off the accelerator and hold the steering wheel steady without sudden braking Correct answer.
  2. Water enters the air intake and hydro-locks the engine cylinders; shift into neutral and restart the engine
  3. Rainwater cools the brake discs below freezing, locking the service brakes; accelerate hard to generate friction heat
  4. Water splashes onto the windshield wipers, causing the wiper motor to reverse polarity; brake hard immediately

Explanation

Hydroplaning occurs when water depth and vehicle speed exceed the tire tread grooves' water evacuation capacity, creating a dynamic water wedge that lifts the tire off the pavement. The vehicle loses steering and braking traction. The driver must remain calm, hold the steering wheel straight and steady, ease off the accelerator to let rolling resistance slow the vehicle, and strictly avoid harsh steering or panic braking.

Question 31Hazards Fitness

If a heavy truck's windshield is shattered by flying gravel on an expressway, completely blocking forward visibility, what immediate actions should the driver take?

  1. Remain calm, look through unbroken glass sections or open the side window for vision, activate hazard flashers, decelerate smoothly, and pull onto the emergency shoulder Correct answer.
  2. Slam on the service brakes immediately and stop in the center travel lane
  3. Punch out the entire glass windshield with both hands while driving at 90 km/h
  4. Accelerate to clear the gravel storm area before looking for a shoulder

Explanation

Laminated truck windshields shatter into an opaque web when struck by heavy stones. The driver must not panic or slam brakes. Open the driver's side window or look through small clear sections/edges of the glass, turn on hazard warning lights, check mirrors, and decelerate progressively onto the emergency shoulder before pushing out shattered fragments.

Question 32China Road Framework

According to Article 48 of the PRC Road Traffic Safety Law Implementation Regulations, when two heavy vehicles meet on a narrow mountain road where passing is difficult, which vehicle has the right of way?

  1. The vehicle driving uphill has priority; however, if the downhill vehicle is already halfway down and the uphill vehicle has not begun climbing, the downhill vehicle passes first Correct answer.
  2. The heavier vehicle always has unconditional right of way regardless of slope direction
  3. The downhill vehicle always has absolute right of way because it cannot apply brakes
  4. The vehicle with the larger engine displacement must always yield to the smaller vehicle

Explanation

Article 48, Item 3 of the Implementation Regulations stipulates that on narrow mountain roads, the vehicle traveling uphill (上坡车) has the right of way because stopping uphill and restarting a loaded truck is difficult and hazardous. However, if the downhill vehicle is already midway on the slope and the uphill vehicle has not yet entered the narrow incline, the downhill vehicle proceeds first.

Question 33China Road Framework

What aerodynamic and environmental hazard occurs when a heavy truck enters or exits a mountain highway tunnel at high speed ('tunnel portal gust' / 狭管效应)?

  1. Sudden lateral wind gusts and lighting transition (black hole/white hole effect) can destabilize vehicle trajectory and impair driver vision Correct answer.
  2. The atmospheric pressure drop inside the tunnel immediately punctures all tubeless tires
  3. Tunnel ventilation exhaust gases cause immediate loss of engine compression
  4. The change in electromagnetic field resets the digital tachograph clock

Explanation

At tunnel portals, the constriction of mountain topography creates a venturi effect (狭管效应), subjecting vehicles to intense localized crosswind gusts. Concurrently, drivers experience the 'black hole' (entering) or 'white hole' (exiting) visual adaptation delay. Drivers must reduce speed before portals, maintain firm two-handed steering control, and turn on low-beam headlights.

Question 34China Road Framework

During extreme summer heatwaves, what is the correct and safe procedure for managing heavy truck tire pressure increases during long-distance highway hauling?

  1. Park in a shaded service area and allow the tires to cool down naturally; NEVER deflate hot tires or pour cold water directly onto hot tires Correct answer.
  2. Immediately bleed air from hot tires until the pressure drops below the winter cold specification
  3. Pour cold water continuously over the hot brake drums and tires while driving
  4. Increase highway speed to 120 km/h so that airflow cools the tire tread surface

Explanation

During high summer temperatures, tire internal pressure naturally rises by 10%–15% due to heat generation. This pressure increase is engineered into tire safety tolerances. Bleeding air out of a hot tire results in severe under-inflation when the tire cools, causing excessive sidewall flexing and explosive blowout. Pouring cold water causes thermal shock, cracking the wheel rims and degrading tire carcass cords.

Question 35China Road Framework

When encountering a severe sandstorm or dust storm (沙尘暴天气) while driving a heavy truck on a highway, what safety measures must the driver take?

  1. Close all windows, turn on fog lights, low beams, and hazard flashers, reduce speed, and park in a safe off-highway service area if visibility collapses Correct answer.
  2. Open all windows to equalize cabin air pressure and increase speed to outrun the dust cloud
  3. Drive on the median dividing strip to avoid dust accumulation in the travel lanes
  4. Turn on high beam headlights and drive in the fast left lane to maintain airflow

Explanation

In dust and sandstorms, visibility drops drastically and fine abrasive sand impairs driver vision and air filters. The driver must close windows, engage external lights (fog lights, clearance lights, hazard flashers), reduce speed, and leave the highway for a designated service area or parking lot if visibility falls below safe operational limits.

Question 36China Road Framework

Where is 'black ice' (暗冰) most commonly formed and hardest to detect on mountain highways during early winter mornings?

  1. On elevated bridge decks, viaducts, shaded mountain curve cuttings, and tunnel portal entrances/exits Correct answer.
  2. On flat sunny highway straightaways exposed to direct solar radiation
  3. Inside heated commercial truck parking garages
  4. Around the hot exhaust tailpipes of stationary trucks

Explanation

Black ice forms when moisture freezes on asphalt without trapping air bubbles, appearing transparent and blending with the dark road. Bridge decks freeze first because cold air circulates both above and below the bridge slab. Shaded mountain switchbacks (背阴路段) and tunnel mouths receive no sunlight, remaining frozen long after ambient temperatures rise.

Question 37China Road Framework

When ordinary non-hazardous freight (如箱装百货、瓜果蔬菜) spills across highway travel lanes following a commercial truck rollover, what is the driver's primary responsibility?

  1. Activate hazard lights, place warning signs upstream at statutory distances, evacuate to safety, report immediately to traffic police (122) and highway maintenance (12122), and assist authorities in scene safety Correct answer.
  2. Stand in the fast lane and physically fight motorists who attempt to drive past
  3. Abandon the scene immediately and hitchhike home without notifying authorities
  4. Set fire to the spilled cargo on the highway to clear the lane quickly

Explanation

Under the PRC Road Traffic Safety Law, when cargo spills and obstructs traffic, the driver must activate hazard lights, place warning triangles upstream to prevent secondary collisions, evacuate beyond the guardrails, and notify traffic police (122) and highway management (12122). The driver must safeguard the scene, prevent looting, and cooperate with road clearing authorities.

Question 38Incident Environment

On ordinary national and provincial highways (普通国省道), what is the statutory placement distance for the reflective warning triangle behind a disabled heavy commercial vehicle?

  1. 50 to 100 meters behind the vehicle Correct answer.
  2. At least 300 meters behind the vehicle
  3. 5 to 10 meters behind the rear tire
  4. Inside the passenger seat footwell

Explanation

Under Article 52 of the Road Traffic Safety Law Implementation Regulations, on ordinary roads (excluding expressways), the reflective warning triangle must be set up 50 to 100 meters behind the vehicle in the direction of oncoming traffic, with hazard warning flashers activated simultaneously.

Question 39Incident Environment

When reporting a highway traffic accident to the police emergency dispatch (122 / 110), what key location information displayed on roadside markers must the driver accurately report?

  1. The expressway route number/name, direction of travel, and exact kilometer post number plus 100-meter marker number (公里桩及百米桩编号) Correct answer.
  2. The name of the driver's hometown and favorite rest stop
  3. The brand of the truck's tires and color of the driver's jacket
  4. The current phase of the moon and ambient air humidity

Explanation

To enable emergency rescue teams (traffic police, fire, ambulances, tow trucks) to locate a crash accurately on long expressway networks, the caller must state: (1) Expressway name/code (e.g., G4 Jinggang'ao Expressway); (2) Driving direction (e.g., southbound toward Guangzhou); (3) Kilometer marker and hundred-meter stake numbers (e.g., K1028 + 400m); (4) Casualties and whether hazardous freight is involved.

Question 40Hazards Fitness

Under MPS Order 163 (道路交通安全违法行为记分管理办法), what is the statutory continuous driving limit and minimum resting period for a medium or heavy freight truck driver?

  1. Continuous driving must not exceed 4 hours without stopping for rest, and each rest period must be at least 20 minutes Correct answer.
  2. Continuous driving must not exceed 6 hours without stopping for rest, and each rest period must be at least 15 minutes
  3. Continuous driving must not exceed 3 hours without stopping for rest, and each rest period must be at least 30 minutes
  4. Continuous driving must not exceed 5 hours without stopping for rest, and each rest period must be at least 10 minutes

Explanation

Under Article 11 of MPS Order 163, driving a medium or heavy freight vehicle continuously for more than 4 hours without stopping to rest, or stopping to rest for less than 20 minutes, is a fatigue driving violation that incurs a 3-point demerit. Drivers must plan their routes to take a minimum 20-minute break in a service area or designated parking zone before reaching the 4-hour threshold.

Question 41Hazards Fitness

Under Article 81 of the Road Traffic Safety Law Implementation Regulations, what actions must a heavy truck driver take when driving on an expressway in dense fog with visibility under 50 meters?

  1. Turn on fog lights, low beams, clearance lamps, and hazard flashers, reduce speed below 20 km/h, and exit the expressway via the nearest exit immediately Correct answer.
  2. Accelerate to 80 km/h to pass through the fog bank as quickly as possible
  3. Stop immediately in the middle travel lane, turn off all vehicle lights, and wait for sunrise
  4. Honk the horn continuously while driving at 60 km/h in the leftmost overtaking lane

Explanation

Under Article 81 of the Implementation Regulations, when expressway visibility is less than 50 meters (dense fog/heavy storm), drivers must activate fog lamps, low beams, position/clearance lamps, and front/rear hazard warning flashers, limit speed to no more than 20 km/h, and leave the expressway at the nearest exit immediately.

Question 42Hazards Fitness

What is the correct driver reaction when a heavy truck encounters strong crosswinds (横风) while crossing a high bridge or emerging from a mountain tunnel?

  1. Grip the steering wheel firmly with both hands, release the accelerator to reduce speed smoothly, and make gentle corrective steering adjustments Correct answer.
  2. Slam on the service brake pedal immediately and yank the steering wheel hard into the wind direction
  3. Shift into neutral and let the wind steer the vehicle onto the shoulder
  4. Accelerate aggressively to maximum speed to cut through the crosswind vortex

Explanation

Sudden crosswinds exert lateral aerodynamic forces against the large surface area of truck boxes and trailers, causing sudden vehicle drift. The driver must maintain a firm two-handed grip on the steering wheel, ease off the throttle to decelerate moderately, and apply gentle, controlled counter-steering. Sudden braking or sharp jerking of the wheel can cause trailer jackknifing or rollover.

Question 43Hazards Fitness

Under Article 48 of the Road Traffic Safety Law Implementation Regulations, what headlight operation is required when meeting an oncoming vehicle at night (夜间会车) on an unlit road?

  1. Switch from high beam (远光灯) to low beam (近光灯) at least 150 meters before reaching the oncoming vehicle, and reduce speed Correct answer.
  2. Keep high beams on continuously to illuminate the oncoming driver's cabin clearly
  3. Turn off all vehicle lights completely to avoid blinding the oncoming vehicle
  4. Activate hazard warning flashers and accelerate past the oncoming vehicle

Explanation

Article 48 of the Implementation Regulations requires drivers to switch from high beam to low beam headlights at a distance of at least 150 meters from oncoming traffic on unlit roads. Drivers should simultaneously reduce speed and focus their gaze on the right roadway edge line to prevent temporary blindness from oncoming glare.

Question 44Hazards Fitness

What is the mandatory emergency protocol if a heavy freight truck stalls or becomes stranded on a railway level crossing (铁路道口) and cannot be restarted or moved?

  1. Immediately get all occupants clear, take every available measure to move the vehicle and any spilled load out of the crossing, and if it cannot be moved at once notify the crossing keeper or railway operator while signalling any approaching train from as far away as possible Correct answer.
  2. Lock the cab doors, sit inside, and honk the truck horn to warn the approaching locomotive to swerve
  3. Unload all heavy cargo onto the railroad tracks to build a defensive barricade
  4. Pour diesel fuel on the rails to reduce train braking friction

Explanation

The Railway Safety Administration Regulations place two duties on a driver whose vehicle or load is stuck in a level crossing: get people clear and move the obstruction out of the crossing by whatever means are available; and, where it cannot be moved immediately, notify the crossing keeper or the railway operator at once and take steps to warn any approaching train. A loaded truck is no match for a train that needs well over a kilometre to stop, so the priority order is people first, then warning, and only then the vehicle.

Question 45Truck Technology

Under Ministry of Transport (MOT) regulations on commercial road freight transport, what document must a heavy truck driver hold in addition to a Public Security motor vehicle driver's license to engage in commercial freight operations legally?

  1. Road Transport Operational Qualification Certificate (道路运输从业资格证) Correct answer.
  2. National Logistics Management Professional Diploma
  3. Special Equipment Operator Certificate issued by the market supervision bureau
  4. Urban Freight Association Honorary Membership Card

Explanation

Under the Regulations of the PRC on Road Transport (道路运输条例) and MOT qualification rules, operating a commercial freight vehicle for business transport requires the driver to hold a valid Road Transport Operational Qualification Certificate (道路运输从业资格证) issued by the transport administrative department, alongside the motor vehicle driving license.

Question 46Truck Technology

According to Article 78 of the Implementation Regulations of the PRC Road Traffic Safety Law, what is the maximum legal speed limit for freight transport vehicles on expressways?

  1. 100 km/h Correct answer.
  2. 120 km/h
  3. 80 km/h
  4. 110 km/h

Explanation

Article 78 of the Road Traffic Safety Law Implementation Regulations specifies that while the maximum speed on expressways is 120 km/h for small passenger cars, the maximum speed for other motor vehicles (including freight trucks) must not exceed 100 km/h (and hazmat vehicles must not exceed 80 km/h).

Question 47Truck Technology

What does a yellow triangular warning sign depicting a truck on a downward slope accompanied by the text 'Engage Low Gear' (货车使用低速挡) instruct the driver to do?

  1. Shift into a low transmission gear before beginning the descent to utilize engine compression braking and retarders Correct answer.
  2. Shift into neutral and coast down the mountain to conserve diesel fuel
  3. Accelerate in the highest gear to overcome upcoming road friction quickly
  4. Turn off the engine ignition to prevent engine overheating during the descent

Explanation

This warning sign is positioned at the crest of steep mountain passes. It mandates that heavy truck drivers downshift into a low mechanical gear before descending, allowing the engine's compression braking resistance to control vehicle speed and preventing continuous friction brake overheating.

Question 48Truck Technology

What is the correct and safe driving practice when operating a heavy truck down a long, steep mountain gradient?

  1. Select a low gear in advance to utilize engine compression braking and auxiliary retarders, avoiding continuous heavy friction braking Correct answer.
  2. Shift the transmission into neutral (空挡) and rely entirely on the service foot brake pedal
  3. Turn off the engine ignition key to save fuel while steering with muscle force
  4. Maintain maximum speed in high gear and apply the emergency handbrake continuously

Explanation

When descending long mountain grades, drivers must downshift to a low gear before the descent. The engine's internal pumping resistance and auxiliary retarders (hydraulic/exhaust) control the vehicle's descent speed, minimizing foundation brake usage and preventing catastrophic brake fade. Coasting in neutral or turning off the ignition is extremely dangerous and illegal.

Question 49Truck Technology

Why is the right-side blind spot of a turning heavy truck commonly referred to as the 'Death Zone' (死亡盲区) for pedestrians and two-wheelers?

  1. Because the elevated cab creates large visual blind spots, and the inner rear wheels track significantly inward (inner wheel difference) sweeping over the sidewalk/corner Correct answer.
  2. Because the truck's exhaust gases immediately blind all nearby cyclists
  3. Because commercial truck turn signals automatically deactivate side rearview mirrors
  4. Because the right side of heavy trucks carries high-voltage electrical charging coils

Explanation

Due to the elevated driver position, high cab doors, and extensive vehicle length, the right side has massive blind zones. Crucially, when turning right, the rear wheels take a tighter path than the front wheels (inner wheel difference / 内轮差). Pedestrians or cyclists standing near the curb who appear clear of the front cab can be trapped and crushed by the inward-tracking rear wheels.

Question 50Truck Technology

What is 'Brake Thermal Fade' (制动器热衰退) in heavy commercial vehicles, and what is the primary method to prevent it?

  1. Friction linings and brake drums overheat from continuous braking, causing friction coefficient loss; prevented by using engine braking and retarders Correct answer.
  2. Brake fluid freezes in winter temperatures; prevented by adding engine anti-freeze into the pneumatic lines
  3. Air compressor belts slip during rain; prevented by applying grease to the alternator pulley
  4. Tire tread melts from high asphalt temperatures; prevented by reducing tire pressure to 2 bar

Explanation

Brake thermal fade occurs when repeated or prolonged friction braking converts excessive kinetic energy into heat (often exceeding 300°C–500°C), causing brake shoe linings to glaze, outgas, and lose friction grip. To prevent thermal fade, drivers must rely on auxiliary deceleration systems (engine compression brake, exhaust brake, hydraulic retarder) and downshifted engine braking to control descent speed.