Take China Truck Subject 4 Practice Questions - China Commercial Vehicle Driving Test Subject 4 Safe and Civilized Driving (大型客货车科目四安全文明驾驶常识) Exam

QUESTION 1 / 25

When a heavy rigid truck or articulated combination vehicle makes a right turn at an urban intersection, what primary factor creates the hazardous right-side blind spot often referred to as the 'Death Zone' (死亡盲区)?

Choose one answer below.

AThe inner wheel difference (内轮差), where the rear wheels follow a significantly tighter turning arc than the front steering wheels✓BThe aerodynamic downforce created by the front bumper deflecting side airflow✓CThe pneumatic brake lag between the foot valve and the trailer relay valve✓DThe reflection of the curb mirror distorting distance perception in direct sunlight✓

QUESTION 2 / 25

How does vehicle wheelbase (轴距) affect the inner wheel difference (内轮差) and turning radius when operating a heavy commercial truck?

Choose one answer below.

AA longer wheelbase produces a larger inner wheel difference, requiring a wider outward swing before turning✓BA longer wheelbase reduces the inner wheel difference, allowing tighter turns near the curb✓CWheelbase length has no mathematical relationship to inner wheel difference, which is governed solely by tire width✓DA shorter wheelbase requires the driver to cross oncoming lanes to avoid curb contact✓

QUESTION 3 / 25

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?

Choose one answer below.

AIt reduces downforce on the front steering axle, leading to degraded steering control and headlight upward mispointing✓BIt causes immediate pneumatic failure of the service brake dual-circuit diaphragm✓CIt locks the transmission inter-axle differential into permanent 4-wheel engagement✓DIt increases front tire temperature and accelerates front tread wear✓

QUESTION 4 / 25

When securing palletized heavy goods on an open flatbed cargo truck, which of the following restraint practices is required under PRC Road Freight Transport Safety Regulations?

Choose one answer below.

AUsing certified ratchet tensioners, tie-down straps, and high-friction rubber dunnage mats across all cargo units✓BRelying solely on the vehicle's side dropsides without additional top-over lashings✓CSecuring only the rearmost pallet and leaving intermediate pallets free to settle naturally✓DTying cargo exclusively with natural hemp ropes secured directly to the wheel rims✓

QUESTION 5 / 25

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?

Choose one answer below.

ATurn the steering wheel to the right initially, then counter-steer to the left once the trailer begins pivoting✓BTurn the steering wheel immediately to the hard left and hold it stationary throughout the maneuver✓CEngage the differential lock and accelerate briskly in reverse without steering inputs✓DPump the service brake pedal continuously while keeping the steering wheel centered✓

QUESTION 6 / 25

Why are liquid tanker trucks (液体罐车) operating with half-empty compartments (30%–70% capacity) exceptionally susceptible to rollover during curve negotiation?

Choose one answer below.

ALiquid sloshing creates a dynamic lateral surge (液体晃动冲击) that drastically shifts the vehicle's center of gravity toward the outside of the turn✓BThe remaining air in the tank creates a vacuum that collapses the tank baffles onto the rear axle✓CPartial liquid loads disable the pneumatic anti-lock braking system (ABS) wheel speed sensors✓DThe lower weight increases engine turbocharger boost beyond the transmission's torque limit✓

QUESTION 7 / 25

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?

Choose one answer below.

AReduce speed well before the ramp entrance curve, maintain a smooth steady arc, and avoid abrupt steering or braking✓BMaintain highway cruising speed until reaching the curve apex, then apply emergency braking✓CCoast through the curve in neutral to allow the high center of gravity to self-stabilize✓DAccelerate sharply through the curve to generate downward aerodynamic downforce✓

QUESTION 8 / 25

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?

Choose one answer below.

AMaximum 4 hours of continuous driving, followed by a mandatory rest stop of at least 20 minutes✓BMaximum 6 hours of continuous driving, followed by a mandatory rest stop of at least 10 minutes✓CMaximum 8 hours of continuous driving, followed by a mandatory rest stop of at least 15 minutes✓DMaximum 5 hours of continuous driving, followed by a mandatory rest stop of at least 30 minutes✓

QUESTION 9 / 25

According to Article 78 of the PRC Road Traffic Safety Law Implementation Regulations, what are the lane usage and maximum speed rules for heavy goods trucks on expressways?

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AHeavy trucks must operate in the right-hand designated lane(s) and must not exceed a maximum speed of 100 km/h✓BHeavy trucks may cruise indefinitely in the far-left overtaking lane at speeds up to 120 km/h✓CHeavy trucks have unrestricted lane choice and are exempt from posted expressway minimum speed limits✓DHeavy trucks must drive on the emergency shoulder whenever their speed falls below 90 km/h✓

QUESTION 10 / 25

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

Choose one answer below.

AThe outward sweep of the vehicle's rear overhang on the opposite side of a turn when pulling away from curbs, walls, or parked vehicles✓BThe lateral vibration of the drive axle caused by an unbalanced driveshaft at highway speeds✓CThe vertical oscillation of the rear air suspension when dumping cargo from a tipper truck✓DThe aerodynamic buffeting of the rear mudflaps in heavy crosswinds✓

QUESTION 11 / 25

According to national standard GB 7258-2017 (Technical Specifications for Safety of Motor Vehicles), what are the mandatory tire tread depth limits and axle restrictions for heavy trucks?

Choose one answer below.

ASteering axle tires must have a tread depth of at least 3.2 mm and must NEVER use retreaded tires; other tires must have at least 1.6 mm✓BAll tires must have a minimum tread depth of 0.8 mm, and retreaded tires are permitted on steering axles if certified✓CSteering axle tires require 1.0 mm tread depth, while drive axle tires require 4.5 mm tread depth✓DTread depth requirements only apply during the annual vehicle inspection and are not checked during roadside enforcement✓

QUESTION 12 / 25

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)?

Choose one answer below.

ATo physically verify that the fifth wheel locking jaws have fully engaged and locked around the trailer kingpin before raising the landing gear✓BTo test whether the engine turbocharger wastegate produces sufficient boost pressure✓CTo calibrate the electronic tire pressure monitoring sensors on the trailer axles✓DTo purge residual moisture and engine oil vapors from the pneumatic air dryer✓

QUESTION 13 / 25

Under national standard GB 1589-2016, what is the standard maximum vehicle height limit for standard commercial freight trucks, and what must a driver do when approaching an overhead height clearance sign (限高标志)?

Choose one answer below.

AMaximum height is 4.0 meters (4.2 meters for standard container chassis); drivers must confirm total loaded height is lower than the posted limit before entering✓BMaximum height is 4.5 meters; trucks may proceed through any underpass if traveling below 20 km/h✓CMaximum height is 3.5 meters; drivers must deflate suspension air springs prior to passing any overpass✓DMaximum height is unlimited on national highways; height restrictions only apply on residential city alleys✓

QUESTION 14 / 25

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)?

Choose one answer below.

AThe front downward cross-view mirror mounted above the windshield to view pedestrians and obstacles immediately adjacent to the front bumper✓BThe interior rearview mirror mounted on the center cab dome✓CThe standard flat main mirror (Class II) mounted on the driver's side door✓DThe aerodynamic rear fender camera used for highway cruising alignment✓

QUESTION 15 / 25

If a heavy truck is loaded with an excessive cantilevered rear overhang load that drastically exceeds statutory limits, what hazardous vehicle dynamic occurs during emergency braking?

Choose one answer below.

ADynamic forward weight transfer lifts the rear axle while the excessive rear polar moment causes rapid tail fishtailing and steering instability✓BThe front brakes automatically disengage to protect the ABS electronic control unit from overvoltage✓CThe engine automatically reverses rotational direction and stalls the transmission✓DThe steering wheel locks permanently in the straight-ahead position due to power steering fluid overpressure✓

QUESTION 16 / 25

Under Ministry of Transport regulations on bulk material transportation (如砂石、土方等散装货物运输), what is the mandatory requirement for open-top dump and freight trucks operating on public roads?

Choose one answer below.

ACargo must not exceed the upper edge of the cargo bed and must be fully covered with an intact tarp or sealed container system✓BCargo may be piled up to 1.5 meters above the side boards if sprayed with adhesive chemical agents✓CTarping is only required during rainy weather and is optional on dry sunny days✓DOpen bulk transport is permitted without covering if vehicle speed is kept below 80 km/h✓

QUESTION 17 / 25

According to Article 80 of the PRC Road Traffic Safety Law Implementation Regulations, what is the minimum following distance a heavy truck must maintain when driving at 100 km/h on an expressway under normal conditions?

Choose one answer below.

AAt least 100 meters✓BAt least 50 meters✓CAt least 30 meters✓DAt least 10 meters✓

QUESTION 18 / 25

When a heavy commercial truck approaches a blind crest or sharp bend on a narrow rural mountain road, what is the proper signaling procedure?

Choose one answer below.

AReduce speed, keep to the right side of the lane, and honk the horn repeatedly to alert oncoming vehicles✓BAccelerate to pass through the blind zone as quickly as possible before another vehicle arrives✓CTurn on hazard warning flashers and drive in the center of the road to claim right of way✓DFlash high beam headlights continuously while maintaining top gear cruising speed✓

QUESTION 19 / 25

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?

Choose one answer below.

AEngage 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✓BEngage permanently during all highway driving to equalize tire wear across tandem axles✓CEngage when descending steep mountain grades to assist the exhaust brake at high speeds✓DEngage only when backing into a loading dock on dry concrete at full steering lock✓

QUESTION 20 / 25

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?

Choose one answer below.

APlacing coils in contoured steel cradles with hardwood wedge chocks (三角木垫) and applying direct heavy-duty chain tie-downs with load binders✓BStacking coils vertically on top of each other without cradles to maximize bed friction✓CRelying on standard synthetic straps without wood chocks or steel cradles✓DPlacing coils loose against the front cab bulkhead so they cannot move further forward✓

QUESTION 21 / 25

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?

Choose one answer below.

AEngage the auxiliary brake in conjunction with a matching low transmission gear to maintain a steady safe speed, minimizing service brake use✓BShift the transmission into neutral and rely solely on the auxiliary exhaust brake✓CUse the service foot brake continuously while leaving the auxiliary brake turned off✓DEngage the auxiliary brake only after the service brakes begin smoking and fading✓

QUESTION 22 / 25

What is the physical mechanism behind 'brake thermal fade' (制动器热衰退) in heavy commercial vehicles on continuous downhill slopes?

Choose one answer below.

AFriction between brake linings and drums generates extreme temperatures exceeding 300°C–500°C, causing the lining friction coefficient to drop drastically✓BExcessive heat causes brake air hoses to freeze and block compressed air delivery✓CHigh temperatures cause the wheel speed sensors to generate magnetic reverse thrust✓DBrake heat causes the transmission torque converter to lock into overdrive ratio✓

QUESTION 23 / 25

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

Choose one answer below.

AIt 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✓BIt clamps carbon ceramic friction discs directly to the driveshaft using high-pressure hydraulic fluid✓CIt injects high-pressure hydraulic fluid into the engine combustion chambers to stop the pistons✓DIt reverses the polarity of the alternator to create an electromagnetic magnetic field in the rear differential✓

QUESTION 24 / 25

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

Choose one answer below.

AHigh retarding torque applied exclusively to the drive axle can cause the drive wheels to break traction and lock/slide, triggering a tractor-trailer jackknife✓BThe retarder will overheat the engine cooling fluid within seconds in sub-zero weather✓CThe hydraulic oil will instantly freeze in the retarder valve block and burst the radiator✓DThe auxiliary brake will deactivate the pneumatic trailer supply line and dump trailer air✓

QUESTION 25 / 25

Why is neutral coasting (空挡滑行) strictly prohibited under the PRC Road Traffic Safety Law Implementation Regulations (Article 62) when descending mountain slopes in a heavy truck?

Choose one answer below.

AIt eliminates engine compression braking, risks engine stalling which cuts power steering, and can deplete pneumatic air compressor supply under repeated braking✓BIt causes the differential gears to spin backwards and seize the rear wheel hubs✓CIt doubles the fuel consumption rate by keeping the engine at maximum idle RPM✓DIt automatically disables the vehicle's ABS computer and triggers emergency brake lockup✓