DVSA Speed and Stopping Distances 4 — Questions and Answers
Question 1: What is the overall stopping distance at 60 mph?
- 36 metres (120 feet)
- 53 metres (175 feet)
- 73 metres (240 feet) (Correct answer)
- 96 metres (315 feet)
Correct answer: 73 metres (240 feet)
At 60 mph, the overall stopping distance is approximately 73 metres (240 feet) — about 18 car lengths. This comprises 18 metres thinking distance and 55 metres braking distance.
Question 2: On an icy road, by how much can stopping distance increase?
- It doubles
- It triples
- Up to 5 times
- Up to 10 times (Correct answer)
Correct answer: Up to 10 times
On icy roads, stopping distances can increase up to 10 times the normal distance. At 30 mph, instead of 23 metres you could need up to 230 metres to stop. Reduce speed dramatically, use the highest gear possible, and brake very gently.
Question 3: How does vehicle weight affect braking distance?
- Heavier vehicles stop more quickly due to better tyre contact
- Heavier vehicles have longer braking distances because more kinetic energy must be dissipated (Correct answer)
- Weight has no effect on modern vehicles
- Only affects vehicles over 3.5 tonnes
Correct answer: Heavier vehicles have longer braking distances because more kinetic energy must be dissipated
A heavier vehicle carries more kinetic energy at any given speed, requiring more braking force and distance to stop. This is why fully loaded vehicles, caravans, and cars with heavy loads need extra following distance. Ensure your load is secure and adjust your driving accordingly.
Question 4: What speed corresponds to approximately 96 metres (315 feet) overall stopping distance?
- 50 mph
- 60 mph
- 70 mph (Correct answer)
- 80 mph
Correct answer: 70 mph
70 mph has an overall stopping distance of approximately 96 metres (315 feet). This is the national speed limit on motorways and dual carriageways, and at this speed you need almost the length of a football pitch to stop.
Question 5: How does an underinflated tyre affect stopping distance?
- It has no effect
- It can increase stopping distance due to poor tyre contact and overheating (Correct answer)
- It reduces stopping distance by increasing grip
- It only affects fuel economy
Correct answer: It can increase stopping distance due to poor tyre contact and overheating
Underinflated tyres have a larger, distorted contact patch that does not grip the road efficiently. They overheat, wear unevenly, and respond poorly to braking and steering. This increases stopping distances and makes the vehicle harder to control. Check tyre pressures regularly when cold.
Question 6: What is the braking distance at 20 mph?
- 3 metres (10 feet)
- 6 metres (20 feet) (Correct answer)
- 9 metres (30 feet)
- 14 metres (45 feet)
Correct answer: 6 metres (20 feet)
At 20 mph, the braking distance is approximately 6 metres (20 feet). Combined with 6 metres thinking distance, the overall stopping distance is 12 metres (40 feet). This is why 20 mph zones are used near schools — the short stopping distance dramatically reduces the severity of any collision.
DVSA Speed and Stopping Distances 4
What is the overall stopping distance at 60 mph?