What is NOT a requirement for commercial vehicles during operation at night?

The requirement that is not necessary for commercial vehicles during nighttime operation is the purchase of extra lighting equipment. While it is crucial for commercial vehicles to be equipped with functioning standard lights, such as headlights, brake lights, and turn signals, there is no legal mandate for them to acquire additional lighting equipment specifically for nighttime driving.

On the other hand, carrying emergency signaling tools is important for safety and compliance; these tools help alert other drivers in case of breakdowns or emergencies. Ensuring the vehicle is parked legally is always a must, regardless of the time of day, to avoid traffic violations and ensure safety. Additionally, using hazard lights when necessary helps to communicate to other drivers that the vehicle is in a potentially dangerous situation, enhancing overall safety on the road. Therefore, while the other options reflect necessary precautions and legal requirements, purchasing extra lighting equipment is not mandated.