63.6. How does the braking distance change when driving an articulated trolleybus not equipped with a braking system?
UAЯк змінюється довжина гальмівного шляху під час руху на зчленованому тролейбусі, не оснащеним гальмівною системою?
Question without image
This is an exam question from the Traffic Rules of Ukraine about braking safety and calculating stopping distance in real driving conditions. It emphasizes that the length of the braking distance is determined not only by speed and road grip, but also by the technical condition of the vehicle and its mass. For the driver, this is directly related to the risk of collision, choice of speed, and the need to maintain a sufficient distance in traffic.
The question tests knowledge of the sections of the traffic rules regarding the choice of safe speed and distance (points 12.1 and 13.1), as well as understanding the requirements for the proper functioning of the braking system (point 31.4.1). In an articulated trolleybus, where the second section does not actually participate in braking, part of the mass continues to move by inertia and "pushes" the front section. Due to less effective deceleration, a greater distance is required for a complete stop, so the braking distance increases.
The analysis of the answer options in this theoretical exam is logical: the statement about a decrease due to "additional trailer resistance" is incorrect, because without brakes, the main factor is not resistance, but the inertia of the additional mass and the lack of braking force on all wheels. The option about no change is also incorrect, since poorer braking performance and greater inertia directly affect the stopping distance. That is why the correct conclusion is that the braking distance increases, and in practice this means: choosing a lower speed, starting to brake earlier, and keeping a greater interval, as required by the traffic rules.
Clause 12.1
When choosing a safe driving speed within the established limits, the driver must take into account the road situation, as well as the characteristics 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.
Brief explanation of the application of the clause: an articulated trolleybus without a braking system (in fact, with reduced braking efficiency/greater inertia) is a "condition and characteristic of the vehicle" that must be taken into account, since in this case the required stopping distance (braking distance) increases.
Clause 13.1
The driver, depending on the speed, road situation, condition of the vehicle, and the cargo being transported, must maintain a safe distance and a safe interval.
Brief explanation of the application of the clause: the requirement for a safe distance is directly related to the length of the braking distance; if the braking distance increases (due to greater mass/poorer braking), the driver must leave a greater distance.
Clause 31.4.1
The operation of vehicles is prohibited under the law if the following technical malfunctions and non-compliance with standard requirements are present: malfunction of the service braking system.
Brief explanation of the application of the clause: the question additionally touches on the importance of the braking system for traffic safety; the absence/malfunction of brakes results in poorer deceleration and, as a consequence, a longer braking distance.
That is, the correct answer is "Increases.", given that according to the definition of the Traffic Rules, the driver is obliged to take into account the condition and characteristics of the vehicle (clause 12.1) and maintain a safe distance (clause 13.1), and a decrease in braking efficiency/increase in vehicle inertia leads to an increase in braking distance.
During braking, the length of the braking distance depends on the speed of movement, the adhesion of the wheels to the road, and how effectively the braking system can create the necessary deceleration for the entire vehicle. According to the Traffic Rules, the requirements for the technical condition of the braking system boil down to the fact that the vehicle must have working brakes that ensure its stop in the established modes, that is, braking must be controlled and sufficiently effective.
An articulated trolleybus consists of two sections. If the second section is not equipped with brakes, then when the brake pedal is pressed, mainly the front part brakes, while the rear section continues to move by inertia and actually "pushes" the front one. As a result, the total mass that needs to be stopped is large, and the braking force is applied not to all wheels, but only to some of them. This reduces the possible deceleration and increases the distance required for a complete stop.
For example, at the same speed and the same road surface, a regular trolleybus with brakes on all necessary axles will stop faster because each section participates in braking. But in an articulated trolleybus without brakes in the trailer section, the front brakes are forced to "pull" the entire train to a stop, so more meters will be needed to stop.
Therefore, the correct answer is "Increases," because when braking an articulated trolleybus without brakes in the second section, part of the mass does not brake, continues to move by inertia, and reduces the effectiveness of the deceleration of the entire vehicle.