Separate reaction distance from braking distance
Reaction distance is the ground covered while you recognise a hazard and respond. Braking distance is the ground covered after braking starts until the vehicle stops. Add both to describe the total stopping distance. Belgian Local Police S.H.A.P.E. explain these three terms.
A useful answer considers the driver, the vehicle and the road. A slower response adds distance before braking. Less available grip changes what happens during braking. Higher speed affects both parts; a distance remembered from a practice question is not a promise that your car will stop within it.
Situation 1: One second before braking
Compare two hypothetical speeds
For this calculation only, assume one second passes between recognising a hazard and starting to brake. Compare travelling at 36 km/h with 72 km/h. How far does the vehicle move during that second?
Check your reasoning
10 metres at 36 km/h; 20 metres at 72 km/h. Divide kilometres per hour by 3.6 to obtain metres per second. Then multiply by the assumed reaction time: 36 ÷ 3.6 × 1 = 10, and 72 ÷ 3.6 × 1 = 20.
These figures include no braking distance. The one-second interval is an explicit teaching assumption, not a measured response time for every driver. If the assumed delay becomes two seconds, the distances become 20 and 40 metres. This is why a question about reaction distance cannot be answered using a braking-distance figure alone.
The European Road Safety Charter's explanation of speed describes the underlying relationship: during the same response time, higher speed carries the vehicle farther. Reducing speed also gives more time for a developing situation to be recognised.
Situation 2: The limit stays the same, the view changes
A bend hides the road ahead
You are below the posted limit on a dry road. Ahead is a bend bordered by a tall hedge. You cannot see whether traffic has stopped beyond it. Does being below the limit establish that your current speed is safe?
Check your reasoning
No. The limited view is a reason to reassess your speed before the bend. You need space for recognising a hazard and stopping, not only space for steering around the visible corner. Do not base the decision on an assumption that the unseen road is empty.
British Highway Code rules 125–126 distinguish a maximum speed limit from a speed suitable for the conditions and advise being able to stop within the clear distance visible ahead. This is cited as British guidance, not a claim that every country uses identical legal wording.
When revising, separate “What speed is legally permitted here?” from “What speed fits the view and hazards now?” The first needs the applicable national limit, signs and vehicle rules. The second needs an assessment of the actual situation. Both questions matter.
Situation 3: Rain begins behind a van
Your old gap now feels familiar
You are following a van when heavy rain begins. Spray reduces the view, and water is collecting on the road. Your following gap has not changed. Is keeping the previous gap a sound response because you have not changed speed?
Check your reasoning
No. The conditions used to judge that gap have changed. Reduce speed appropriately and allow more separation. Account for the reduced view as well as the road surface; do not wait for the van to brake before recognising the need for more room.
Transport Scotland's bad-weather guidance recommends lower speed, greater stopping space and avoiding abrupt acceleration or braking. It also explains that wet roads can substantially extend stopping distance. A familiar route or functioning brakes do not remove the change in conditions.
In a practice explanation, name both changes: poorer visibility can delay recognition, while reduced grip can increase braking distance. Saying only “rain is dangerous” misses the reason for adjusting your driving.
Review the assumptions behind a number
Whenever a test gives a stopping-distance figure, check the stated speed, response time and road conditions. Ask whether it describes reaction distance, braking distance or the total. Do not transfer a dry-road example to ice or assume a time-gap recommendation is a universal legal minimum.
Denmark's category B curriculum, section 9.2.3, discusses braking force, speed, grip, downhill gradients and the additional distance associated with the driver's response. Use national guidance and your instructor for the requirements relevant to your test. These original scenarios are independent learning exercises; instructor review of TheoryTestEU remains pending. See our sources and correction policy.