Which of the following is NOT a factor to consider for PSD manning requirements?

The choice of not considering past incidents of travel as a factor for PSD (Protective Security Detail) manning requirements highlights an important aspect of situational analysis in protective operations. While the history of incidents may provide context or insights into potential risks, it is not as directly relevant to current manning decisions as the other factors listed.

Duration of travel, the vulnerability of the Human Resources Personnel (HRP), and the location of the HRP are critical factors that require immediate attention when assessing security needs. The duration of travel affects how long the PSD team must be engaged and may influence staffing levels to ensure adequate coverage throughout the journey. The vulnerability of the HRP is crucial as it directly impacts the level of threat they may face, thus determining the necessary resources and personnel allocation. Lastly, the location of the HRP is significant because different environments present varying levels of risk, and understanding these locales can help tailor the PSD's strategies and manning.

In contrast, past incidents may not accurately reflect the current threat landscape or operational needs, and basing decisions on historical data without considering current circumstances could lead to inadequately prepared security measures. Thus, this choice aligns with a more proactive and contextual approach to PSD manning requirements.