Which of the following factors determines to the greatest extent the length of an agricultural tractor's braking distance during emergency braking?
Show the correct answer
Correct answer
A. The type of the road surface.
Explanation
In the photo there is a view from the tractor cab, over a red bonnet, of a yard paved with paving blocks, with snow lying at its edge. The length of a tractor's stopping distance during emergency braking depends most on the type and condition of the road surface and the weather conditions - answer A.
The stopping distance is the distance travelled during the driver's reaction time plus the braking distance itself. At the same speed, it is the grip of the tyres on the road that decides how quickly the tractor loses speed: on dry asphalt it stops in the shortest distance, on wet asphalt in a clearly longer one, and on mud, snow or ice - in a distance even several times longer. The mass of the driver (answer B) is tiny compared with the mass of the tractor. The maximum permissible mass (answer C) is a value in the vehicle registration certificate, not the actual state of the vehicle, and it says nothing about the conditions on the road. In winter, as in the photo, you drive more slowly and brake earlier, because there may be frost even on paving blocks or asphalt that look dry.
Legal basis: Art. 19 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)