Reaction, braking and total stopping distance
First you sense the danger and react. Then you start braking. The total includes both parties.
Practice
Reaction time · Braking distance · Total stopping distance
Reaction Space
It is the path from the moment you sense danger until the start of braking. In this interval the braking has not yet begun.
Total stopping distance
It is the sum of reaction space and space during braking. The braking space is a part of the total, not its synonym.
Try to explain it
Without opening the answers, it indicates which stage comes first and which starts with braking. Then compare the two examples.
Test the concept
True or false?
The space traveled in reaction time is that traveled from the moment of perception of a danger situation to that of starting braking
Italian text
Lo spazio percorso nel tempo di reazione è quello percorso dal momento della percezione di una situazione di pericolo a quello di inizio della frenata
Answer and explanation
Correct answer: TRUE
Reaction space is the stretch between two moments: when you sense danger and when you start to brake. At this stage the braking has not yet begun; the sentence does not establish an equal reaction time for everyone.
True or false?
The safe distance must be maintained to avoid frontal collision
Italian text
La distanza di sicurezza deve essere mantenuta per evitare lo scontro frontale
Answer and explanation
Correct answer: FALSE
The distance from the vehicle in front is about the rear, not the frontal collision. The reaction space ranges from the perception of danger to the start of braking. It's just a phase of the arrest. The safe distance protects against rear-end collisions and cannot be reduced under the space needed to react.
True or false?
The braking space is the one traveled from the start of braking to the stop of the vehicle
Italian text
Lo spazio di frenatura è quello percorso dall'inizio della frenata all'arresto del veicolo
Answer and explanation
Correct answer: TRUE
The braking space begins when the brake starts and ends at the stop. In theoretical comparison with the other conditions it grows with the square of speed: double speed, four times the space. Comparison is not a universal measure on the road.
True or false?
Braking space is independent of speed
Italian text
Lo spazio di frenatura è indipendente dalla velocità
Answer and explanation
Correct answer: FALSE
Speed affects the braking space. The braking space begins when the brake starts and ends at the stop. In theoretical comparison with the other conditions it grows with the square of speed: double speed, four times the space. Comparison is not a universal measure on the road.
True or false?
The total stopping space is equal to the space traveled in reaction time plus that traveled during braking
Italian text
Lo spazio totale di arresto è pari allo spazio percorso nel tempo di reazione più quello percorso durante la frenata
Answer and explanation
Correct answer: TRUE
The total stopping space includes the stroke traveled during the reaction plus the stroke during braking. Therefore the braking space is one of two parts, not a synonym for the total. A numerical distance to be used when driving is not calculated here.
True or false?
Total stopping space is independent of tyre wear
Italian text
Lo spazio totale di arresto è indipendente dall'usura dei pneumatici
Answer and explanation
Correct answer: FALSE
Tire wear can affect the braking phase and therefore the total. The total stopping space sum reaction and braking. Speed, tires and asphalt affect the result. Confusing the total with a single phase eliminates part of the path.