63.7. How should the trolleybus driver act if it starts drizzling while driving on a dry road with asphalt concrete pavement?
UAЯк слід вчинити водієві тролейбуса, якщо під час руху сухою дорогою з асфальтобетонним покриттям почав накрапати дощ?
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This is an exam question from the Traffic Rules of Ukraine about road safety in conditions of sudden changes in the road environment, when the surface of dry asphalt concrete begins to get wet. For a trolleybus, this situation is especially important due to its large mass, the transportation of passengers, and increased requirements for smooth handling: at the beginning of rain, the wheel grip with the road can sharply deteriorate, and the braking distance can increase significantly. That is why questions that teach drivers to react in advance, rather than wait until the road is "completely wet," are often included in the theoretical exam.
In essence, this task tests knowledge of the sections of the Traffic Rules regarding the driver's duties and the choice of a safe speed: the driver must be attentive and respond appropriately to changes in the situation (para. 2.3), choose speed taking into account the condition of the surface (para. 12.1), immediately take measures to reduce speed in case of danger (para. 12.3), and maintain a safe distance (para. 13.1). The start of rain on a city road is often accompanied by the formation of a slippery film of dust and oil residues, so "caution" here means smooth deceleration, avoiding sharp maneuvers, and increasing the distance.
The correct option is the one that provides for reducing speed and increased caution: this gives extra time and distance for braking and helps maintain control. Driving without changing speed ignores the drop in the coefficient of adhesion and the increase in braking distance, which contradicts the requirements of the traffic rules regarding safe speed. And the attempt to "rush through" is the riskiest: higher speed and inertia make braking and turning more dangerous, increase the likelihood of skidding, and create a threat to passengers and other road users, which directly contradicts the logic of the exam question for the theoretical test.
Clause 2.3 (subclause "b")
The driver is obliged to: be attentive, monitor the road situation, respond appropriately to its changes, monitor the correct placement and securing of the load, the technical condition of the vehicle, and not be distracted from driving this vehicle on the road.
The beginning of rain is a change in the road situation (in particular, the condition of the surface and traction), so the trolleybus driver must respond accordingly and act cautiously.
Clause 12.1
When choosing a safe driving speed within the established limits, the driver must take into account the road situation, the specifics of the cargo being transported, and the condition of the vehicle in order to be able to constantly control its movement and drive it safely.
When the asphalt concrete surface begins to get wet, the safe speed decreases, so the driver must reduce speed to maintain control of the trolleybus.
Clause 12.3
If a danger to traffic or an obstacle that the driver can objectively detect arises, he must immediately take measures to reduce speed up to stopping the vehicle or safely bypassing the obstacle for other road users.
The onset of rain on dry asphalt objectively creates an increased risk of skidding, so the proper action is to immediately reduce speed and make maneuvers/braking as smoothly as possible.
Clause 13.1
The driver, depending on the speed, road situation, specifics of the cargo being transported, and the condition of the vehicle, must maintain a safe distance.
With reduced traction and increased braking distance during rain, it is necessary, in particular, to increase the distance (as an element of "being cautious").
That is, the correct answer is "Reduce speed and be cautious," given that according to the definition of the Traffic Rules, the driver is obliged to be attentive and respond to changes in the road situation (clause 2.3), choose a safe speed taking into account the condition of the surface (clause 12.1), immediately reduce speed in case of danger (clause 12.3), and maintain a safe distance (clause 13.1).
When a trolleybus is moving on a dry asphalt concrete road and it starts to drizzle, the wheel grip conditions with the surface change immediately, not “later, when the road gets wet.” At this moment, the main task for the driver is to adjust the speed in advance to the new road conditions, in order to maintain control and have enough distance for stopping.
The Traffic Rules require the driver to choose a safe speed taking into account the condition of the road surface and visibility, and also to drive the vehicle in such a way as to be able to constantly control its movement and safely stop within the visible section of the road. As soon as the first drops of rain appear, the coefficient of adhesion to the asphalt decreases, and the braking distance increases. For a trolleybus, which has significant mass and carries passengers, this is especially critical: sudden braking or abrupt maneuvers can cause skidding and dangerous jolts for people in the cabin.
It is also important to remember the most dangerous moment — the beginning of the rain. The first drops mix with dust, oil residues, and other contaminants on the road, forming a thin slippery film. Externally, the surface may appear only slightly darkened, but in terms of vehicle behavior, it already “acts” as very slippery. Therefore, it is at the beginning of the rain that the risk of losing traction during braking or turning is higher than on uniformly wet asphalt.
Practically correct actions for the trolleybus driver in such a situation are to reduce speed in advance and smoothly, avoid sudden braking and abrupt steering, increase the distance to vehicles ahead, and be prepared for a longer braking distance. For example, when approaching a stop or intersection, it is advisable to start slowing down earlier than on a dry road and to do so as evenly as possible to avoid skidding.
Thus, the correct answer is "Reduce speed and be cautious," because at the beginning of rain, traction with asphalt sharply deteriorates, braking distance increases, and the Traffic Rules require choosing a safe speed and driving the vehicle so as to maintain full control in the changed road conditions.