Which factor often affects training operations conducted on public streets or in parking lots?

Training operations conducted on public streets or in parking lots are significantly influenced by vehicle traffic. When training takes place in these environments, the presence of traffic can create hazards for both participants and the general public. It is crucial for instructors to account for the flow of vehicles, which may necessitate altering the timing or location of training exercises to ensure safety. This includes coordinating with local traffic authorities if necessary and implementing measures to minimize the risk of accidents or injuries during training activities.

The other factors, while important in their own contexts, do not present the same level of immediate risk during such operations. Lighting can affect visibility but may not always be a primary concern during the day or in well-lit areas. Water supply is essential for many training scenarios but is less relevant to training in urban environments where vehicle traffic is present. The enforcement of safety cone and vest use is vital for enhancing visibility and safety but doesn't address the dynamic risk posed by moving vehicles in the area.