What factor does NOT significantly influence driver retention according to the provided content?

The factor that does not significantly influence driver retention is the personal responsibility of drivers. While personal responsibility is important in ensuring that drivers adhere to safety regulations and perform their tasks effectively, it does not directly impact the broader systematic factors that contribute to driver retention within a company.

In the context of driver retention, elements such as recruitment processes, involvement of upper management, and company culture play a more crucial role. Recruitment processes can ensure that the right candidates are chosen who align with the organization's values and the demands of the job, leading to more satisfactory long-term employment. The involvement of upper management is critical as it sets the tone for workplace practices, supports initiatives that improve job satisfaction, and demonstrates a commitment to employee safety and well-being. Similarly, company culture shapes the working environment, influences employee engagement, and retains drivers by creating a sense of belonging and satisfaction within the workplace.

In summary, while personal responsibility is a valuable trait for drivers, it does not encompass the broader organizational factors that are essential in retaining drivers, making it a lesser influence in the context of driver retention strategies.