You are driving along an exposed dual carriageway during severe gales and are overtaking a high-sided commercial vehicle. Which TWO aerodynamic effects must you be prepared to handle during this manoeuvre? (Select TWO answers)
- A sudden pull towards the commercial vehicle when entering the sheltered wind shadow along its sideAnswer
- BA complete loss of front-wheel traction requiring you to disengage the clutch and coast until clear
- A violent lateral buffet pushing your car across the lane as you move past the front of the cabAnswer
- DAn immediate requirement to apply emergency braking to prevent the vehicle from skidding sideways
Answer
Anticipating a sudden pull towards the commercial vehicle in its wind shadow, and preparing for a violent lateral buffet as you move past the front of the cab.
When passing a large high-sided vehicle in severe crosswinds, two major aerodynamic transitions occur. First, moving alongside the trailer places your car into a sheltered wind shadow where the wind is blocked, causing an apparent suction effect towards the lorry. Second, clearing the front of the cab suddenly re-exposes your car to the full force of the wind, causing a sharp lateral gust that pushes you outwards across the lane.
Step-by-Step Solution
Key Concept
Aerodynamic buffeting and wind shadows when overtaking high-sided vehicles in severe gales
Estimated Time:1m 15s