PCV Skid Prevention and Defensive Driving 1 — Questions and Answers
Question 1: What is the most common cause of skidding in a bus or coach?
- Driving too slowly
- Excessive speed for the road conditions (Correct answer)
- Underinflated tyres only
- Passengers moving to the upper deck
Correct answer: Excessive speed for the road conditions
Skids are most often caused by driving too fast for the prevailing road and weather conditions.
Skids occur when tyres lose grip with the road surface. The most common cause is excessive speed for the conditions — whether wet roads, ice, loose gravel, or sharp bends. A PCV driver must constantly assess road conditions and adjust speed well in advance. Prevention is always preferable to correction.
Question 2: If the rear of a bus begins to skid to the right (oversteer), what should the driver do?
- Brake heavily and steer left
- Steer gently into the skid (to the right) and avoid harsh braking (Correct answer)
- Apply the handbrake
- Accelerate to pull the vehicle straight
Correct answer: Steer gently into the skid (to the right) and avoid harsh braking
Steering into the direction of the skid (the direction the rear is moving) helps the driver regain control.
In a rear-wheel oversteer skid, the rear of the vehicle slides to one side. The driver should steer in the same direction as the skid — if the rear goes right, steer right. Braking or opposite lock usually worsens the situation. Once the rear comes back into line, smoothly straighten the steering to prevent an opposite skid.
Question 3: What does 'defensive driving' mean for a PCV driver?
- Driving as close to the kerb as possible
- Anticipating hazards and adjusting driving to keep a safe space cushion around the vehicle (Correct answer)
- Driving slowly at all times regardless of conditions
- Avoiding motorways and dual carriageways
Correct answer: Anticipating hazards and adjusting driving to keep a safe space cushion around the vehicle
Defensive driving means anticipating hazards ahead and maintaining safe space to respond without emergency manoeuvres.
Defensive driving for PCV operators involves: scanning well ahead for hazards, maintaining safe following distances, adjusting speed smoothly in advance of bends and junctions, keeping a space cushion around the vehicle, and never assuming other road users will behave predictably. The DVSA promote this as fundamental to professional bus and coach driving.
Question 4: On a downhill gradient, which driving technique best prevents brake fade in a fully loaded coach?
- Riding the footbrake continuously
- Using a lower gear to provide engine braking rather than relying solely on the footbrake (Correct answer)
- Switching off the engine and coasting
- Applying the parking brake intermittently
Correct answer: Using a lower gear to provide engine braking rather than relying solely on the footbrake
Engine braking via a lower gear reduces brake temperature and prevents brake fade on descents.
Brake fade occurs when sustained heavy brake use overheats the braking system, reducing its effectiveness. PCV drivers should select an appropriate lower gear before starting a descent, using engine braking to control speed, with the footbrake used only for supplementary control. This preserves brake effectiveness throughout the descent.
Question 5: What is the stopping distance of a double-deck bus travelling at 30 mph on a wet road compared to a dry road?
- Roughly the same
- About twice as long (Correct answer)
- About four times as long
- About ten times as long
Correct answer: About twice as long
On a wet road, stopping distances for large vehicles roughly double compared to dry conditions.
Wet roads reduce tyre-to-road friction significantly, roughly doubling the braking distance. For a loaded bus, the effect is compounded by the vehicle's mass. Drivers should at least double their normal following distance in wet conditions. Black ice can increase stopping distances by up to ten times. Anticipation is the key to safe braking on large vehicles.
Question 6: What is the recommended safe following distance for a coach travelling at 60 mph on a dry motorway?
- 1 second
- 2 seconds
- At least 3 seconds (greater on large vehicles) (Correct answer)
- 10 metres
Correct answer: At least 3 seconds (greater on large vehicles)
A minimum 2-second gap is advised for cars; large vehicles should use at least 3 seconds or the 'metre per tonne' rule.
The Highway Code recommends at least a 2-second gap from the vehicle in front at 60 mph. For large PSVs, the DVSA advises applying the 'metre per tonne' rule — approximately 1 metre per tonne of gross vehicle weight — or a minimum of 3 seconds. In wet or adverse conditions this should be at least doubled.
PCV Skid Prevention and Defensive Driving 1
What is the most common cause of skidding in a bus or coach?